.. _parameters:
Enzo Parameter List
===================
The following is a largely complete list of the parameters that Enzo
understands, and a brief description of what they mean. They are grouped
roughly by meaning; an alphabetical list is also available. Parameters for
individual test problems are also listed here.
This parameter list has two purposes. The first is to describe and explain the
parameters that can be put into the initial parameter file that begins a run.
The second is to provide a comprehensive list of all parameters that the code
uses, including those that go into an output file (which contains a complete
list of all parameters), so that users can better understand these output
files.
The parameters fall into a number of categories:
**external**
These are user parameters in the sense that they can be set in the
parameter file, and provide the primary means of communication
between Enzo and the user.
**internal**
These are mostly not set in the parameter file (although strictly
speaking they can be) and are generally used for program to
communicate with itself (via the restart of output files).
**obsolete**
No longer used.
**reserved**
To be used later.
Generally the external parameters are the only ones that are modified or set,
but the internal parameters can provide useful information and can sometimes be
modified so I list them here as well. Some parameters are true/false or on/off
boolean flags. Eventually, these may be parsed, but in the meantime, we use the
common convention of 0 meaning false or off and 1 for true or on.
This list includes parameters for the Enzo 2.0 release.
.. highlight:: none
Stopping Parameters
-------------------
``StopTime`` (external)
This parameter specifies the time (in code units) when the
calculation will halt. For cosmology simulations, this variable is
automatically set by ``CosmologyFinalRedshift``. *No default.*
``StopCycle`` (external)
The cycle (top grid timestep) at which the calculation stops. A
value of zero indicates that this criterion is not be used.
*Default: 100,000*
``StopFirstTimeAtLevel`` (external)
Causes the simulation to immediately stop when a specified level is
reached. Default value 0 (off), possible values are levels 1
through maximum number of levels in a given simulation.
``NumberOfOutputsBeforeExit`` (external)
After this many datadumps have been written, the code will exit. If
set to 0 (default), this option will not be used. Default: 0.
``StopCPUTime`` (external)
Causes the simulation to stop if the wall time exceeds ``StopCPUTime``.
The simulation will output if the wall time after the next
top-level timestep will exceed ``StopCPUTime``, assuming that the wall
time elapsed during a top-level timestep the same as the previous
timestep. In units of seconds. Default: 2.592e6 (30 days)
``ResubmitOn`` (external)
If set to 1, the simulation will stop if the wall time will exceed
``StopCPUTime`` within the next top-level timestep and run a shell
script defined in ``ResubmitCommand`` that should resubmit the job
for the user. Default: 0.
``ResubmitCommand`` (external)
Filename of a shell script that creates a queuing (e.g. PBS)
script from two arguments, the number of processors and parameter
file. This script is run by the root processor when stopping with
``ResubmitOn``. An example script can be found in
input/resubmit.sh. Default: (null)
Initialization Parameters
-------------------------
``ProblemType`` (external)
This integer specifies the type of problem to be run. Its value
causes the correct problem initializer to be called to set up the
grid, and also may trigger certain boundary conditions or other
problem-dependent routines to be called. The possible values are
listed below. Default: none.
For other problem-specific parameters follow the links below. The problems
marked with "hydro_rk" originate from the MUSCL solver package in the enzo installation directory
``src/enzo/hydro_rk``. For the 4xx radiation hydrodynamics problem types, see
the user guides in the installation directory ``doc/implicit_fld`` and ``doc/split_fld``.
============ ====================================
Problem Type Description and Parameter List
============ ====================================
1 :ref:`shocktube_param`
2 :ref:`wavepool_param`
3 :ref:`shockpool_param`
4 :ref:`doublemach_param`
5 :ref:`shockinabox_param`
6 Implosion
7 SedovBlast
8 KH Instability
9 2D/3D Noh Problem
10 :ref:`rotatingcylinder_param`
11 :ref:`radiatingshock_param`
12 :ref:`freeexpansion_param`
20 :ref:`zeldovichpancake_param`
21 :ref:`pressurelesscollapse_param`
22 :ref:`adiabaticexpansion_param`
23 :ref:`testgravity_param`
24 :ref:`sphericalinfall_param`
25 :ref:`testgravitysphere_param`
26 :ref:`gravityequilibriumtest_param`
27 :ref:`collapsetest_param`
28 TestGravityMotion
29 TestOrbit
30 :ref:`cosmologysimulation_param`
31 :ref:`galaxysimulation_param`
35 :ref:`shearingbox_param`
40 :ref:`supernovarestart_param`
50 :ref:`photontest_param`
60 Turbulence Simulation
61 Protostellar Collapse
62 :ref:`coolingtest_param`
101 3D Collapse Test (hydro_rk)
102 1D Spherical Collapse Test (hydro_rk)
106 Hydro and MHD Turbulence Simulation (hydro_rk)
107 Put Sink from restart
200 1D MHD Test
201 2D MHD Test
202 3D MHD Collapse Test
203 MHD Turbulent Collapse Test
207 Galaxy disk
208 AGN disk
300 Poisson solver test
400 Radiation-Hydrodynamics test 1 -- constant fields
401 Radiation-Hydrodynamics test 2 -- stream test
402 Radiation-Hydrodynamics test 3 -- pulse test
403 Radiation-Hydrodynamics test 4 -- grey Marshak test
404/405 Radiation-Hydrodynamics test 5 -- radiating shock test
410/411 Radiation-Hydrodynamics test 10/11 -- Static HI ionization
412 Radiation-Hydrodynamics test 12 -- HI ionization of a clump
413 Radiation-Hydrodynamics test 13 -- HI ionization of a steep region
414/415 Radiation-Hydrodynamics test 14/15 -- Cosmological HI ionization
450-452 Free-streaming radiation tests
============ ====================================
.. raw:: html
``TopGridRank`` (external)
This specifies the dimensionality of the root grid and by extension
the entire hierarchy. It should be 1,2 or 3. Default: none
``TopGridDimensions`` (external)
This is the dimension of the top or root grid. It should consist of
1, 2 or 3 integers separated by spaces. For those familiar with the
KRONOS or ZEUS method of specifying dimensions, these values do not
include ghost or boundary zones. A dimension cannot be less than 3
zones wide and more than ``MAX_ANY_SINGLE_DIRECTION`` -
``NumberOfGhostZones``\*2. ``MAX_ANY_SINGLE_DIRECTION`` is defined in
``fortran.def``. Default: none
``DomainLeftEdge``, ``DomainRightEdge`` (external)
These float values specify the two corners of the problem domain
(in code units). The defaults are: 0 0 0 for the left edge and 1 1
1 for the right edge.
``LeftFaceBoundaryCondition``, ``RightFaceBoundaryCondition`` (external)
These two parameters each consist of vectors of integers (of length
``TopGridRank``). They specify the boundary conditions for the top grid
(and hence the entire hierarchy). The first integer corresponds to
the x-direction, the second to the y-direction and the third, the
z-direction. The possible values are: 0 - reflecting, 1 - outflow,
2 - inflow, 3 - periodic, 4 - shearing. For inflow, the inflow
values can be set through the next parameter, or more commonly are
controlled by problem-specific code triggered by the ``ProblemType``.
For shearing boundaries, the boundary pair in another direction
must be periodic. Note that self gravity will not be consistent
with shearing boundary conditions. Default: 0 0 0
``ShearingVelocityDirection`` (external)
Select direction of shearing boundary. Default is x direction. Changing this is probably not a good idea.
``AngularVelocity`` (external)
The value of the angular velocity in the shearing boundary.
Default: 0.001
``VelocityGradient`` (external)
The value of the per code length gradient in the angular velocity
in the shearing boundary. Default: 1.0
``BoundaryConditionName`` (external)
While the above parameters provide an easy way to set an entire
side of grid to a given boundary value, the possibility exists to
set the boundary conditions on an individual cell basis. This is
most often done with problem specific code, but it can also be set
by specifying a file which contains the information in the
appropriate format. This is too involved to go into here. Default:
none
``InitialTime`` (internal)
The time, in code units, of the current step. For cosmology the
units are in free-fall times at the initial epoch (see :ref:`EnzoOutputFormats`). Default: generally 0, depending on problem
``Initialdt`` (internal)
The timestep, in code units, for the current step. For cosmology
the units are in free-fall times at the initial epoch (see :ref:`EnzoOutputFormats`). Default: generally 0, depending on problem
Simulation Identifiers and UUIDs
--------------------------------
These parameters help to track, identify and group datasets. For reference,
`Universally Unique Identifiers
`_ (UUIDs) are
opaque identifiers using random 128-bit numbers, with an extremely low chance
of collision. (See :ref:`SimulationNamesAndIdentifiers` for a longer
description of these parameters.)
``MetaDataIdentifier`` (external)
This is a character string without spaces (specifically, something
that can be picked by "%s"), that can be defined in a parameter
file, and will be written out in every following output, if it is
found.
``MetaDataSimulationUUID`` (internal)
A UUID that will be written out in all of the following outputs.
Like ``MetaDataIdentifier``, an existing UUID will be kept, but if one
is not found, and new one will be generated.
``MetaDataDatasetUUID`` (internal)
A UUID created for each specific output.
``MetaDataRestartDatasetUUID`` (internal)
If a ``MetaDataDatasetUUID`` UUID is found when the parameter file is
read in, it will written to the following datasets. This is used to
track simulations across restarts and parameter adjustments.
``MetaDataInitialConditionsUUID`` (internal)
This is similar to ``MetaDataRestartDatasetUUID``, except it's used to
track which initial conditions were used.
I/O Parameters
--------------
There are three ways to specify the frequency of outputs:
time-based, cycle-based (a cycle is a top-grid timestep), and, for
cosmology simulations, redshift-based. There is also a shortened
output format intended for visualization (movie format). Please
have a look at :ref:`controlling_data_output` for more information.
``dtDataDump`` (external)
The time interval, in code units, between time-based outputs. A
value of 0 turns off the time-based outputs. Default: 0
``CycleSkipDataDump`` (external)
The number of cycles (top grid timesteps) between cycle-based
outputs. Zero turns off the cycle-based outputs. Default: 0
``DataDumpName`` (external)
The base file name used for both time and cycle based outputs.
Default: data
``RedshiftDumpName`` (external)
The base file name used for redshift-based outputs (this can be
overridden by the ``CosmologyOutputRedshiftName`` parameter). Normally
a four digit identification number is appended to the end of this
name, starting from 0000 and incrementing by one for every output.
This can be over-ridden by including four consecutive R's in the
name (e.g. RedshiftRRRR) in which case the an identification number
will not be appended but the four R's will be converted to a
redshift with an implied decimal point in the middle (i.e. z=1.24
becomes 0124). Default: RedshiftOutput
``CosmologyOutputRedshift[NNNN]`` (external)
The time and cycle-based outputs occur regularly at constant
intervals, but the redshift outputs are specified individually.
This is done by the use of this statement, which sets the output
redshift for a specific identification number (this integer is
between 0000 and 9999 and is used in forming the name). So the
statement ``CosmologyOutputRedshift[1] = 4.0`` will cause an output to
be written out at z=4 with the name RedshiftOutput0001 (unless the
base name is changed either with the previous parameter or the next
one). This parameter can be repeated with different values for the
number (NNNN) Default: none
``CosmologyOutputRedshiftName[NNNN]`` (external)
This parameter overrides the parameter ``RedshiftOutputName`` for this
(only only this) redshift output. Can be used repeatedly in the
same manner as the previous parameter. Default: none
``OutputFirstTimeAtLevel`` (external)
This forces Enzo to output when a given level is reached, and at
every level thereafter. Default is 0 (off). User can usefully
specify anything up to the maximum number of levels in a given
simulation.
``FileDirectedOutput``
If this parameter is set to 1, whenever the finest level has finished
evolving Enzo will check for new signal files to output. (See
:ref:`force_output_now`.) Default 1.
``XrayLowerCutoffkeV``, ``XrayUpperCutoffkeV``, ``XrayTableFileName`` (external)
These parameters are used in 2D projections (``enzo -p ...``). The
first two specify the X-ray band (observed at z=0) to be used, and
the last gives the name of an ascii file that contains the X-ray
spectral information. A gzipped version of this file good for
bands within the 0.1 - 20 keV range is provided in the
distribution in ``input/lookup_metal0.3.data``. If these
parameters are specified, then the second field is replaced with
integrated emissivity along the line of sight in units of 10\
:sup:`-23` erg/cm\ :sup:`2`/s. Default: ``XrayLowerCutoffkeV =
0.5``, ``XrayUpperCutoffkeV = 2.5``.
``ExtractFieldsOnly`` (external)
Used for extractions (enzo -x ...) when only field data are needed
instead of field + particle data. Default is 1 (TRUE).
``dtRestartDump``
Reserved for future use.
``dtHistoryDump``
Reserved for future use.
``CycleSkipRestartDump``
Reserved for future use.
``CycleSkipHistoryDump``
Reserved for future use.
``RestartDumpName``
Reserved for future use.
``HistoryDumpName``
Reserved for future use.
``ParallelRootGridIO`` (external)
Normally for the mpi version, the root grid is read into the root
processor and then partitioned to separate processors using communication.
However, for
very large root grids (e.g. 512\ :sup:`3`\ ), the root processor
may not have enough memory. If this toggle switch is set on (i.e.
to the value 1), then each processor reads its own section of the
root grid. More I/O is required (to split up the grids and
particles), but it is more balanced in terms of memory.
``ParallelRootGridIO`` and ``ParallelParticleIO`` MUST be set to 1 (TRUE)
for runs involving > 64 cpus! Default: 0 (FALSE). See also ``Unigrid``
below.
``Unigrid`` (external)
This parameter should be set to 1 (TRUE) for large cases--AMR as
well as non-AMR--where the root grid is 512\ :sup:`3`\ or larger.
This prevents initialization under subgrids at start up, which is
unnecessary in cases with simple non-nested initial conditions.
Unigrid must be set to 0 (FALSE) for cases with nested initial
conditions. Default: 0 (FALSE). See also ``ParallelRootGridIO`` above.
``UnigridTranspose`` (external)
This parameter governs the fast FFT bookkeeping for Unigrid runs.
Does not work with isolated gravity. Default: 0 (FALSE). See also
``Unigrid`` above.
``OutputTemperature`` (external)
Set to 1 if you want to output a temperature field in the datasets.
Always 1 for cosmology simulations. Default: 0.
``OutputCoolingTime`` (external)
Set to 1 if you want to output the cooling time in the datasets.
Default: 0.
``OutputSmoothedDarkMatter`` (external)
Set to 1 if you want to output a dark matter density field,
smoothed by an SPH kernel. Set to 2 to also output smoothed dark
matter velocities and velocity dispersion. Set to 0 to turn off.
Default: 0.
``OutputGriddedStarParticle`` (external)
Set to 1 or 2 to write out star particle data gridded onto mesh.
This will be useful e.g. if you have lots of star particles in a
galactic scale simulation. 1 will output just
``star_particle_density``; and 2 will dump
``actively_forming_stellar_mass_density``, ``SFR_density``, etc.
Default: 0.
``VelAnyl`` (external)
Set to 1 if you want to output the divergence and vorticity of
velocity. Works in 2D and 3D.
``BAnyl`` (external)
Set to 1 if you want to output the divergence and vorticity of
``Bfield``. Works in 2D and 3D.
``SmoothedDarkMatterNeighbors`` (external)
Number of nearest neighbors to smooth dark matter quantities over.
Default: 32.
.. _streaming_param:
Streaming Data Format
~~~~~~~~~~~~~~~~~~~~~
``NewMovieLeftEdge``, ``NewMovieRightEdge`` (external)
These two parameters control the region for which the streaming
data are written. Default: ``DomainLeftEdge`` and ``DomainRightEdge``.
``MovieSkipTimestep`` (external)
Controls how many timesteps on a level are skipped between outputs
in the streaming data. Streaming format is off if this equals
``INT_UNDEFINED``. Default: ``INT_UNDEFINED``
``Movie3DVolume`` (external)
Set to 1 to write streaming data as 3-D arrays. This should always
be set to 1 if using the streaming format. A previous version had
2D maximum intensity projections, which now defunct. Default: 0.
``MovieVertexCentered`` (external)
Set to 1 to write the streaming data interpolated to vertices. Set
to 0 for cell-centered data. Default: 0.
``NewMovieDumpNumber`` (internal)
Counter for streaming data files. This should equal the cycle
number.
``MovieTimestepCounter`` (internal)
Timestep counter for the streaming data files.
``MovieDataField`` (external)
A maximum of 6 data fields can be written in the streaming format.
The data fields are specified by the array element of
BaryonField, i.e. 0 = Density, 7 = HII
Density. For writing temperature, a special value of 1000 is used.
This should be improved to be more transparent in which fields will
be written. Any element that equals ``INT_UNDEFINED`` indicates no
field will be written. Default: ``INT_UNDEFINED`` x 6
``NewMovieParticleOn`` (external)
Set to 1 to write all particles in the grids. Set to 2 to write
ONLY particles that aren't dark matter, e.g. stars. Set to 3/4 to
write ONLY particles that aren't dark matter into a file separate
from the grid info. (For example, ``MoviePackParticle_P000.hdf5``,
etc. will be the file name; this will be very helpful in speeding
up the access to the star particle data, especially for the
visualization or for the star particle. See ``AMRH5writer.C``) Set to 0
for no particle output. Default: 0.
Hierarchy Control Parameters
----------------------------
``StaticHierarchy`` (external)
A flag which indicates if the hierarchy is static (1) or dynamic
(0). In other words, a value of 1 takes the A out of AMR. Default:
1
``RefineBy`` (external)
This is the refinement factor between a grid and its subgrid. For
cosmology simulations, we have found a ratio of 2 to be most useful.
Default: 4
``MaximumRefinementLevel`` (external)
This is the lowest (most refined) depth that the code will produce.
It is zero based, so the total number of levels (including the root
grid) is one more than this value. Default: 2
``CellFlaggingMethod`` (external)
The method(s) used to specify when a cell should be refined. This
is a list of integers, up to 9, as described by the following
table. The methods combine in an "OR" fashion: if any of them
indicate that a cell should be refined, then it is flagged. For
cosmology simulations, methods 2 and 4 are probably most useful.
Note that some methods have additional parameters which are
described below. Default: 1
::
1 - refine by slope 6 - refine by Jeans length
2 - refine by baryon mass 7 - refine if (cooling time < cell width/sound speed)
3 - refine by shocks 11 - refine by resistive length
4 - refine by particle mass 12 - refine by defined region "MustRefineRegion"
5 - refine by baryon overdensity 13 - refine by metallicity
(currently disabled)
101 - avoid refinement in regions
defined in "AvoidRefineRegion"
``RefineRegionLeftEdge``, ``RefineRegionRightEdge`` (external)
These two parameters control the region in which refinement is
permitted. Each is a vector of floats (of length given by the
problem rank) and they specify the two corners of a volume.
Default: set equal to ``DomainLeftEdge`` and ``DomainRightEdge``.
``RefineRegionAutoAdjust`` (external)
This is useful for multiresolution simulations with particles in
which the particles have varying mass. Set to 1 to automatically
adjust the refine region at root grid timesteps to only contain
high-resolution particles. This makes sure that the fine regions do
not contain more massive particles which may lead to small
particles orbiting them or other undesired outcomes. Setting to any
integer (for example, 3) will make AdjustRefineRegion to work at
(RefineRegionAutoAdjust-1)th level timesteps because sometimes the
heavy particles are coming into the fine regions too fast that you
need more frequent protection. Default: 0.
``RefineRegionTimeType`` (external)
If set, this controls how the first column of a refinement region
evolution file (see below) is interpreted, 0 for code time, 1 for
redshift. Default: -1, which is equivalent to 'off'.
``RefineRegionFile`` (external)
The name of a text file containing the corners of the time-evolving
refinement region. The lines in the file change the values of
``RefineRegionLeft/RightEdge`` during the course of the simulation, and
the lines are ordered in the file from early times to late times.
The first column of data is the time index (in code units or
redshift, see the parameter above) for the next six columns, which
are the values of ``RefineRegionLeft/RightEdge``. For example, this
might be two lines from the text file when time is indexed by
redshift:
::
0.60 0.530 0.612 0.185 0.591 0.667 0.208
0.55 0.520 0.607 0.181 0.584 0.653 0.201
In this case, the refinement region stays at the z=0.60 value
until z=0.55, when the box moves slightly closer to the (0,0,0)
corner. There is a maximum of 300 lines in the file and there is no
comment header line. Default: None.
``MinimumOverDensityForRefinement`` (external)
These float values (up to 9) are used if the
``CellFlaggingMethod`` is 2, 4 or 5. For method 2 and 4, the value is the density (baryon or particle), in code units, above which refinement occurs. When using method 5, it becomes rho [code] - 1. The elements in this array must match those in ``CellFlaggingMethod``. Therefore, if ``CellFlaggingMethod`` = 1 4 9 10, ``MinimumOverDensityForRefinement`` = 0 8.0 0 0.
In practice, this value is converted into a mass by
multiplying it by the volume of the top grid cell. The result is
then stored in the next parameter (unless that is set directly in
which case this parameter is ignored), and this defines the mass
resolution of the simulation. Note that the volume is of a top grid
cell, so if you are doing a multi-grid initialization, you must
divide this number by r\ :sup:`(d\*l)`\ where r is the refinement
factor, d is the dimensionality and l is the (zero-based) lowest
level. For example, for a two grid cosmology setup where a cell should be
refined whenever the mass exceeds 4 times the mean density of the
subgrid, this value should be 4 / (2\ :sup:`(3\*1)`\ ) = 4 / 8 =
0.5. Keep in mind that this parameter has no effect if it is
changed in a restart output; if you want to change the refinement
mid-run you will have to modify the next parameter. Up to 9
numbers may be specified here, each corresponding to the respective
``CellFlaggingMethod``. Default: 1.5
``MinimumMassForRefinement`` (internal)
This float is usually set by the parameter above and so is labeled
internal, but it can be set by hand. For non-cosmological simulations, it can be the easier refinement criteria to specify. It is the mass above
which a refinement occurs if the ``CellFlaggingMethod`` is
appropriately set. For cosmological simulations, it is specified in units such
that the entire mass in the computational volume is 1.0, otherwise it is in code units. There are 9 numbers here again, as per the
above parameter. Default: none
``MinimumMassForRefinementLevelExponent`` (external).
This parameter modifies the behaviour of the above parameter. As it
stands, the refinement based on the ``MinimumMassForRefinement``
(hereafter Mmin) parameter is complete Lagrangian. However, this
can be modified. The actual mass used is
Mmin\*r\ :sup:`(l\*alpha)`\ where r is the refinement factor, l is
the level and alpha is the value of this parameter
(``MinimumMassForRefinementLevelExponent``). Therefore a negative value
makes the refinement super-Lagrangian, while positive values are
sub-Lagrangian. There are up to 9 values specified here, as per
the above two parameters. Default: 0.0
``SlopeFlaggingFields[#]`` (external)
If ``CellFlaggingMethod`` is 1, and you only want to refine on the
slopes of certain fields then you can enter the number IDs of the
fields. Default: Refine on slopes of all fields.
``MinimumSlopeForRefinement`` (external)
If ``CellFlaggingMethod`` is 1, then local gradients are used as the
refinement criteria. All variables are examined and the relative
slope is computed: abs(q(i+1)-q(i-1))/q(i). Where this value
exceeds this parameter, the cell is marked for refinement. This
causes problems if q(i) is near zero. This is a single integer (as
opposed to the list of five for the above parameters). Entering
multiple numbers here correspond to the fields listed in
``SlopeFlaggingFields``. Default: 0.3
``MinimumPressureJumpForRefinement`` (external)
If refinement is done by shocks, then this is the minimum
(relative) pressure jump in one-dimension to qualify for a shock.
The definition is rather standard (see Colella and Woodward's PPM
paper for example) Default: 0.33
``MinimumEnergyRatioForRefinement`` (external)
For the dual energy formalism, and cell flagging by
shock-detection, this is an extra filter which removes weak shocks
(or noise in the dual energy fields) from triggering the shock
detection. Default: 0.1
``MetallicityRefinementMinLevel`` (external)
Sets the minimum level (maximum cell size) to which a cell enriched
with metal above a level set by ``MetallicityRefinementMinMetallicity``
will be refined. This can be set to any level up to and including
``MaximumRefinementLevel``. (No default setting)
``MetallicityRefinementMinMetallicity`` (external)
This is the threshold metallicity (in units of solar metallicity)
above which cells must be refined to a minimum level of
``MetallicityRefinementMinLevel``. Default: 1.0e-5
``MustRefineRegionMinRefinementLevel`` (external)
Minimum level to which the rectangular solid volume defined by
``MustRefineRegionLeftEdge`` and ``MustRefineRegionRightEdge`` will be
refined to at all times. (No default setting)
``MustRefineRegionLeftEdge`` (external)
Bottom-left corner of refinement region. Must be within the overall
refinement region. Default: 0.0 0.0 0.0
``MustRefineRegionRightEdge`` (external)
Top-right corner of refinement region. Must be within the overall
refinement region. Default: 1.0 1.0 1.0
``MustRefineParticlesRefineToLevel`` (external)
The maximum level on which ``MustRefineParticles`` are required to
refine to. Currently sink particles and MBH particles are required
to be sitting at this level at all times. Default: 0
``MustRefineParticlesRefineToLevelAutoAdjust`` (external)
The parameter above might not be handy in cosmological simulations
if you want your ``MustRefineParticles`` to be refined to a certain
physical length, not to a level whose cell size keeps changing.
This parameter (positive integer in pc) allows you to do just that.
For example, if you set ``MustRefineParticlesRefineToLevelAutoAdjust``
= 128 (pc), then the code will automatically calculate
``MustRefineParticlesRefineToLevel`` using the boxsize and redshift
information. Default: 0 (FALSE)
``FluxCorrection`` (external)
This flag indicates if the flux fix-up step should be carried out
around the boundaries of the sub-grid to preserve conservation (1 -
on, 0 - off). Strictly speaking this should always be used, but we
have found it to lead to a less accurate solution for cosmological
simulations because of the relatively sharp density gradients
involved. However, it does appear to be important when radiative
cooling is turned on and very dense structures are created.
It does work with the ZEUS
hydro method, but since velocity is face-centered, momentum flux is
not corrected. Species quantities are not flux corrected directly
but are modified to keep the fraction constant based on the density
change. Default: 1
``InterpolationMethod`` (external)
There should be a whole section devoted to the interpolation
method, which is used to generate new sub-grids and to fill in the
boundary zones of old sub-grids, but a brief summary must suffice.
The possible values of this integer flag are shown in the table
below. The names specify (in at least a rough sense) the order of
the leading error term for a spatial Taylor expansion, as well as a
letter for possible variants within that order. The basic problem
is that you would like your interpolation method to be:
multi-dimensional, accurate, monotonic and conservative. There
doesn't appear to be much literature on this, so I've had to
experiment. The first one (ThirdOrderA) is time-consuming and
probably not all that accurate. The second one (SecondOrderA) is
the workhorse: it's only problem is that it is not always
symmetric. The next one (SecondOrderB) is a failed experiment, and
SecondOrderC is not conservative. FirstOrderA is everything except
for accurate. If HydroMethod = 2 (ZEUS), this flag is ignored, and
the code automatically uses SecondOrderC for velocities and
FirstOrderA for cell-centered quantities. Default: 1
::
0 - ThirdOrderA 3 - SecondOrderC
1 - SecondOrderA 4 - FirstOrderA
2 - SecondOrderB
``ConservativeInterpolation`` (external)
This flag (1 - on, 0 - off) indicates if the interpolation should
be done in the conserved quantities (e.g. momentum rather than
velocity). Ideally, this should be done, but it can cause problems
when strong density gradients occur. This must(!) be set off for
ZEUS hydro (the code does it automatically). Default: 1
``MinimumEfficiency`` (external)
When new grids are created during the rebuilding process, each grid
is split up by a recursive bisection process that continues until a
subgrid is either of a minimum size or has an efficiency higher
than this value. The efficiency is the ratio of flagged zones
(those requiring refinement) to the total number of zones in the
grid. This is a number between 0 and 1 and should probably by
around 0.4 for standard three-dimensional runs. Default: 0.2
``NumberOfBufferZones`` (external)
Each flagged cell, during the regridding process, is surrounded by
a number of zones to prevent the phenomenon of interest from
leaving the refined region before the next regrid. This integer
parameter controls the number required, which should almost always
be one. Default: 1
``RefineByJeansLengthSafetyFactor`` (external)
If the Jeans length refinement criterion (see ``CellFlaggingMethod``)
is being used, then this parameter specifies the number of cells
which must cover one Jeans length. Default: 4
``JeansRefinementColdTemperature`` (external)
If the Jeans length refinement criterion (see ``CellFlaggingMethod``)
is being used, and this parameter is greater than zero, it will be
used in place of the temperature in all cells. Default: -1.0
``StaticRefineRegionLevel[#]`` (external)
This parameter is used to specify regions of the problem that are
to be statically refined, regardless of other parameters. This is mostly
used as an internal mechanism to keep the initial grid hierarchy in
place, but can be specified by the user. Up to 20 static regions
may be defined (this number set in ``macros_and_parameters.h``), and
each static region is labeled starting from zero. For each static
refined region, two pieces of information are required: (1) the
region (see the next two parameters), and (2) the level at which
the refinement is to occurs (0 implies a level 1 region will always
exist). Default: none
``StaticRefineRegionLeftEdge[#]``, ``StaticRefineRegionRightEdge[#]`` (external)
These two parameters specify the two corners of a statically
refined region (see the previous parameter). Default: none
``AvoidRefineRegionLevel[#]`` (external)
This parameter is used to limit the refinement to this level in a
rectangular region. Up to MAX_STATIC_REGIONS regions can be used.
``AvoidRefineRegionLeftEdge[#]``, ``AvoidRefineRegionRightEdge[#]`` (external)
These two parameters specify the two corners of a region that
limits refinement to a certain level (see the previous
parameter). Default: none
``RefineByResistiveLength`` (external)
Resistive length is defined as the curl of the magnetic field over
the magnitude of the magnetic field. We make sure this length is
covered by this number of cells. Default: 2
``LoadBalancing`` (external)
Set to 0 to keep child grids on the same processor as their
parents. Set to 1 to balance the work on one level over all
processors. Set to 2 or 3 to load balance the grids but keep them
on the same node. Option 2 assumes grouped scheduling, i.e. proc #
= (01234567) reside on node (00112233) if there are 4 nodes. Option
3 assumes round-robin scheduling (proc = (01234567) -> node =
(01230123)). Set to 4 for load balancing along a Hilbert
space-filling curve on each level. Default: 1
``LoadBalancingCycleSkip`` (external)
This sets how many cycles pass before we load balance the root
grids. Only works with LoadBalancing set to 2 or 3. NOT RECOMMENDED
for nested grid calculations. Default: 10
Hydrodynamic Parameters
-----------------------
``UseHydro`` (external)
This flag (1 - on, 0 - off) controls whether a hydro solver is used.
Default: 1
``HydroMethod`` (external)
This integer specifies the hydrodynamics method that will be used.
Currently implemented are
============ =============================
Hydro method Description
============ =============================
0 PPM DE (a direct-Eulerian version of PPM)
1 [reserved]
2 ZEUS (a Cartesian, 3D version of Stone & Norman). Note that if ZEUS is selected, it automatically turns off ``ConservativeInterpolation`` and the ``DualEnergyFormalism`` flags.
3 Runge Kutta second-order based MUSCL solvers.
4 Same as 3 but including Dedner MHD (Wang & Abel 2008). For 3 and 4 there are the additional parameters ``RiemannSolver`` and ``ReconstructionMethod`` you want to set.
============ =============================
Default: 0
More details on each of the above methods can be found at :ref:`hydro_methods`.
``RiemannSolver`` (external; only if ``HydroMethod`` is 3 or 4)
This integer specifies the Riemann solver used by the MUSCL solver. Choice of
============== ===========================
Riemann solver Description
============== ===========================
0 [reserved]
1 HLL (Harten-Lax-van Leer) a two-wave, three-state solver with no resolution of contact waves
2 [reserved]
3 LLF (Local Lax-Friedrichs)
4 HLLC (Harten-Lax-van Leer with Contact) a three-wave, four-state solver with better resolution of contacts
5 TwoShock
============== ===========================
Default: 1 (HLL) for ``HydroMethod`` = 3; 5 (TwoShock) for
``HydroMethod`` = 0
``RiemannSolverFallback`` (external)
If the euler update results in a negative density or energy, the
solver will fallback to the HLL Riemann solver that is more
diffusive only for the failing cell. Only active when using the
HLLC or TwoShock Riemann solver. Default: OFF.
``ReconstructionMethod`` (external; only if ``HydroMethod`` is 3 or 4)
This integer specifies the reconstruction method for the MUSCL solver. Choice of
===================== ====================
Reconstruction Method Description
===================== ====================
0 PLM (piecewise linear)
1 PPM (piecwise parabolic)
2 [reserved]
3 [reserved]
4 [reserved]
===================== ====================
Default: 0 (PLM) for ``HydroMethod`` = 3; 1 (PPM) for ``HydroMethod`` = 0
``Gamma`` (external)
The ratio of specific heats for an ideal gas (used by all hydro
methods). If using multiple species (i.e. ``MultiSpecies`` > 0), then
this value is ignored in favor of a direct calculation (except for
PPM LR) Default: 5/3.
``Mu`` (external)
The molecular weight. Default: 0.6.
``ConservativeReconstruction`` (external)
Experimental. This option turns on the reconstruction of the
left/right interfaces in the Riemann problem in the conserved
variables (density, momentum, and energy) instead of the primitive
variables (density, velocity, and pressure). This generally gives
better results in constant-mesh problems has been problematic in
AMR simulations. Default: OFF
``PositiveReconstruction`` (external)
Experimental and not working. This forces the Riemann solver to
restrict the fluxes to always give positive pressure. Attempts to
use the Waagan (2009), JCP, 228, 8609 method. Default: OFF
``CourantSafetyNumber`` (external)
This is the maximum fraction of the CFL-implied timestep that will
be used to advance any grid. A value greater than 1 is unstable
(for all explicit methods). The recommended value is 0.4. Default:
0.6.
``RootGridCourantSafetyNumber`` (external)
This is the maximum fraction of the CFL-implied timestep that will
be used to advance ONLY the root grid. When using simulations with
star particle creation turned on, this should be set to a value of
approximately 0.01-0.02 to keep star particles from flying all over
the place. Otherwise, this does not need to be set, and in any case
should never be set to a value greater than 1.0. Default: 1.0.
``DualEnergyFormalism`` (external)
The dual energy formalism is needed to make total energy schemes
such as PPM DE and PPM LR stable and accurate in the
"hyper-Machian" regime (i.e. where the ratio of thermal energy to
total energy < ~0.001). Turn on for cosmology runs with PPM DE and
PPM LR. Automatically turned off when used with the hydro method
ZEUS. Integer flag (0 - off, 1 - on). When turned on, there are two
energy fields: total energy and thermal energy. Default: 0
``DualEnergyFormalismEta1``, ``DualEnergyFormalismEta2`` (external)
These two parameters are part of the dual energy formalism and
should probably not be changed. Defaults: 0.001 and 0.1
respectively.
``PressureFree`` (external)
A flag that is interpreted by the PPM DE hydro method as an
indicator that it should try and mimic a pressure-free fluid. A
flag: 1 is on, 0 is off. Default: 0
``PPMFlatteningParameter`` (external)
This is a PPM parameter to control noise for slowly-moving shocks.
It is either on (1) or off (0). Default: 0
``PPMDiffusionParameter`` (external)
This is the PPM diffusion parameter (see the Colella and Woodward
method paper for more details). It is either on (1) or off (0).
Default: 1 [Currently disabled (set to 0)]
``PPMSteepeningParameter`` (external)
A PPM modification designed to sharpen contact discontinuities. It
is either on (1) or off (0). Default: 0
``ZEUSQuadraticArtificialViscosity`` (external)
This is the quadratic artificial viscosity parameter C2 of Stone &
Norman, and corresponds (roughly) to the number of zones over which
a shock is spread. Default: 2.0
``ZEUSLinearArtificialViscosity`` (external)
This is the linear artificial viscosity parameter C1 of Stone &
Norman. Default: 0.0
Magnetohydrodynamic Parameters
------------------------------
``UseDivergenceCleaning`` (external)
Method 1 and 2 are a failed experiment to do divergence cleaning
using successive over relaxation. Method 3 uses conjugate gradient
with a 2 cell stencil and Method 4 uses a 4 cell stencil. 4 is more
accurate but can lead to aliasing effects. Default: 0
``DivergenceCleaningBoundaryBuffer`` (external)
Choose to *not* correct in the active zone of a grid by a
boundary of cells this thick. Default: 0
``DivergenceCleaningThreshold`` (external)
Calls divergence cleaning on a grid when magnetic field divergence
is above this threshold. Default: 0.001
``PoissonApproximateThreshold`` (external)
Controls the accuracy of the resulting solution for divergence
cleaning Poisson solver. Default: 0.001
``ResetMagneticField`` (external)
Set to 1 to reset the magnetic field in the regions that are denser
than the critical matter density. Very handy when you want to
re-simulate or restart the dumps with MHD. Default: 0
``ResetMagneticFieldAmplitude`` (external)
The magnetic field values (in Gauss) that will be used for the
above parameter. Default: 0.0 0.0 0.0
Cosmology Parameters
--------------------
``ComovingCoordinates`` (external)
Flag (1 - on, 0 - off) that determines if comoving coordinates are
used or not. In practice this turns on or off the entire cosmology
machinery. Default: 0
``CosmologyFinalRedshift`` (external)
This parameter specifies the redshift when the calculation will
halt. Default: 0.0
``CosmologyOmegaMatterNow`` (external)
This is the contribution of all non-relativistic matter (including
HDM) to the energy density at the current epoch (z=0), relative to
the value required to marginally close the universe. It includes
dark and baryonic matter. Default: 0.279
``CosmologyOmegaLambdaNow`` (external)
This is the contribution of the cosmological constant to the energy
density at the current epoch, in the same units as above. Default:
0.721
``CosmologyComovingBoxSize`` (external)
The size of the volume to be simulated in Mpc/h (at z=0). Default:
64.0
``CosmologyHubbleConstantNow`` (external)
The Hubble constant at z=0, in units of 100 km/s/Mpc. Default:
0.701
``CosmologyInitialRedshift`` (external)
The redshift for which the initial conditions are to be generated.
Default: 20.0
``CosmologyMaxExpansionRate`` (external)
This float controls the timestep so that cosmological terms are
accurate followed. The timestep is constrained so that the relative
change in the expansion factor in a step is less than this value.
Default: 0.01
``CosmologyCurrentRedshift`` (information only)
This is not strictly speaking a parameter since it is never
interpreted and is only meant to provide information to the user.
Default: n/a
Gravity Parameters
------------------
``TopGridGravityBoundary`` (external)
A single integer which specified the type of gravitational boundary
conditions for the top grid. Possible values are 0 for periodic and
1 for isolated (for all dimensions). The isolated boundary
conditions have not been tested recently, so caveat emptor.
Default: 0
``SelfGravity`` (external)
This flag (1 - on, 0 - off) indicates if the baryons and particles
undergo self-gravity.
``GravitationalConstant`` (external)
This is the gravitational constant to be used in code units. For cgs units it
should be 4\*pi\*G. For cosmology, this value must be 1 for the
standard units to hold. A more detailed decription can be found at :ref:`EnzoInternalUnits`. Default: 4\*pi.
``GreensFunctionMaxNumber`` (external)
The Green's functions for the gravitational potential depend on the
grid size, so they are calculated on a as-needed basis. Since they
are often re-used, they can be cached. This integer indicates the
number that can be stored. They don't take much memory (only the
real part is stored), so a reasonable number is 100. [Ignored in
current version]. Default: 1
``GreensFunctionMaxSize``
Reserved for future use.
``S2ParticleSize`` (external)
This is the gravitational softening radius, in cell widths, in
terms of the S2 particle described by Hockney and Eastwood in their
book Computer Simulation Using Particles. A reasonable value is
3.0. [Ignored in current version]. Default: 3.0
``GravityResolution`` (external)
This was a mis-guided attempt to provide the capability to increase
the resolution of the gravitational mesh. In theory it still works,
but has not been recently tested. Besides, it's just not a good
idea. The value (a float) indicates the ratio of the gravitational
cell width to the baryon cell width. [Ignored in current version].
Default: 1
``PotentialIterations`` (external)
Number of iterations to solve the potential on the subgrids. Values
less than 4 sometimes will result in slight overdensities on grid
boundaries. Default: 4.
``BaryonSelfGravityApproximation`` (external)
This flag indicates if baryon density is derived in a strange,
expensive but self-consistent way (0 - off), or by a completely
reasonable and much faster approximation (1 - on). This is an
experiment gone wrong; leave on. Well, actually, it's important for
very dense structures as when radiative cooling is turned on, so
set to 0 if using many levels and radiative cooling is on [ignored
in current version]. Default: 1
``MaximumGravityRefinementLevel`` (external)
This is the lowest (most refined) depth that a gravitational
acceleration field is computed. More refined levels interpolate
from this level, provided a mechanism for instituting a minimum
gravitational smoothing length. Default: ``MaximumRefinementLevel``
(unless ``HydroMethod`` is ZEUS and radiative cooling is on, in which
case it is ``MaximumRefinementLevel`` - 3).
``MaximumParticleRefinementLevel`` (external)
This is the level at which the dark matter particle contribution to
the gravity is smoothed. This works in an inefficient way (it
actually smoothes the particle density onto the grid), and so is
only intended for highly refined regions which are nearly
completely baryon dominated. It is used to remove the discreteness
effects of the few remaining dark matter particles. Not used if set
to a value less than 0. Default: -1
External Gravity Source
~~~~~~~~~~~~~~~~~~~~~~~~
These parameters set-up an external static background gravity source that is
added to the acceleration field for the baryons and particles.
``PointSourceGravity`` (external)
This parameter indicates that there is to be a
(constant) gravitational field with a point source profile (``PointSourceGravity`` =
1) or NFW profile (``PointSourceGravity`` = 2). Default: 0
``PointSourceGravityConstant`` (external)
If ``PointSourceGravity`` = 1, this is the magnitude of the point
source acceleration at a distance of 1
length unit (i.e. GM in code units). If ``PointSourceGravity`` =
2, then it takes the mass of the dark matter halo in CGS
units. ``ProblemType`` = 31 (galaxy disk simulation) automatically calculates
values for ``PointSourceGravityConstant`` and
``PointSourceGravityCoreRadius``. Default: 1
``PointSourceGravityCoreRadius`` (external)
For ``PointSourceGravity`` = 1, this is the radius inside which
the acceleration field is smoothed in code units. With ``PointSourceGravity`` =
2, it is the scale radius, rs, in CGS units (see Navarro, Frank & White,
1997). Default: 0
``PointSourceGravityPosition`` (external)
If the ``PointSourceGravity`` flag is turned on, this parameter
specifies the center of the point-source gravitational field in
code units. Default: 0 0 0
``ExternalGravity`` (external)
This fulfills the same purpose as ``PointSourceGravity`` but is
more aptly named. ``ExternalGravity = 1`` turns on an alternative
implementation of the NFW profile with properties
defined via the parameters ``HaloCentralDensity``, ``HaloConcentration`` and ``HaloVirialRadius``. Boxsize is assumed to be 1.0 in this case. ``ExternalGravity = 10`` gives a gravitational field defined by the logarithmic potential in Binney & Tremaine, corresponding to a disk with constant circular velocity. Default: 0
``ExternalGravityConstant`` (external)
If ``ExternalGravity = 10``, this is the circular velocity of the disk in code units. Default: 0.0
``ExternalGravityDensity``
Reserved for future use.
``ExternalGravityPosition`` (external)
If ``ExternalGravity = 10``, this parameter specifies the center of the gravitational field in code units. Default: 0 0 0
``ExternalGravityOrientation`` (external)
For ``ExternalGravity = 10``, this is the unit vector of the disk's angular momentum (e.g. a disk whose face-on view is oriented in the x-y plane would have ``ExternalGravityOrientation = 0 0 1``). Default: 0 0 0
``ExternalGravityRadius`` (external)
If ``ExternalGravity = 10``, this marks the inner radius of the disk in code units within which the velocity drops to zero. Default: 0.0
``UniformGravity`` (external)
This flag (1 - on, 0 - off) indicates if there is to be a uniform
gravitational field. Default: 0
``UniformGravityDirection`` (external)
This integer is the direction of the uniform gravitational field: 0
- along the x axis, 1 - y axis, 2 - z axis. Default: 0
``UniformGravityConstant`` (external)
Magnitude (and sign) of the uniform gravitational acceleration.
Default: 1
Particle Parameters
-------------------
``ParticleBoundaryType`` (external)
The boundary condition imposed on particles. At the moment, this
parameter is largely ceremonial as there is only one type
implemented: periodic, indicated by a 0 value. Default: 0
``ParticleCourantSafetyNumber`` (external)
This somewhat strangely named parameter is the maximum fraction of
a cell width that a particle is allowed to travel per timestep
(i.e. it is a constant on the timestep somewhat along the lines of
it's hydrodynamic brother). Default: 0.5
``NumberOfParticles`` (obsolete)
Currently ignored by all initializers, except for TestGravity and
TestGravitySphere where it is the number of test points. Default: 0
``NumberOfParticleAttributes`` (internal)
It is set to 3 if either ``StarParticleCreation`` or
``StarParticleFeedback`` is set to 1 (TRUE). Default: 0
``AddParticleAttributes`` (internal)
If set to 1, additional particle attributes will be added and
zeroed. This is handy when restarting a run, and the user wants to
use star formation afterwards. Default: 0.
``ParallelParticleIO`` (external)
Normally, for the mpi version, the particle data are read into the
root processor and then distributed to separate processors.
However, for very large number of particles, the root processor may
not have enough memory. If this toggle switch is set on (i.e. to
the value 1), then Ring i/o is turned on and each processor reads
its own part of the particle data. More I/O is required, but it is
more balanced in terms of memory. ``ParallelRootGridIO`` and
``ParallelParticleIO`` MUST be set for runs involving > 64 cpus!
Default: 0 (FALSE).
``ParticleSplitterIterations`` (external)
Set to 1 to split particles into 13 particles (= 12 children+1
parent, Kitsionas & Whitworth (2002)). This should be ideal for
setting up an low-resolution initial condition for a relatively low
computational cost, running it for a while, and then restarting it
for an extremely high-resolution simulation in a focused region.
Currently it implicitly assumes that only DM (type=1) and
conventional star particles (type=2) inside the ``RefineRegion`` get
split. Other particles, which usually become Star class objects,
seem to have no reason to be split. Default: 0
``ParticleSplitterChildrenParticleSeparation`` (external)
This is the spacing between the child particles placed on a
hexagonal close-packed (HCP) array. In the unit of a cell size
which the parent particle resides in. Default: 1.0
Parameters for Additional Physics
---------------------------------
``RadiativeCooling`` (external)
This flag (1 - on, 0 - off) controls whether or not a radiative
cooling module is called for each grid. There are currently several
possibilities, controlled by the value of another flag. See :ref:`cooling`
for more information on the various cooling methods. Default: 0
- If the ``MultiSpecies`` flag is off, then equilibrium cooling is
assumed and one of the following two will happen. If the parameter
``GadgetCooling`` is set to 1, the primordial equilibrium code is
called (see below). If ``GadgetCooling`` is set to 0, a file called
``cool_rates.in`` is read to set a cooling curve. This file consists
of a set of temperature and the associated cgs cooling rate; a
sample compute with a metallicity Z=0.3 Raymond-Smith code is
provided in ``input/cool_rates.in``. This has a cutoff at 10000 K
(Sarazin & White 1987). Another choice will be
``input/cool_rates.in_300K`` which goes further down to 300 K (Rosen
& Bregman 1995).
- If the ``MultiSpecies`` flag is on, then the cooling rate is
computed directly by the species abundances. This routine (which
uses a backward differenced multi-step algorithm) is borrowed
from the Hercules code written by Peter Anninos and Yu Zhang,
featuring rates from Tom Abel. Other varieties of cooling are
controlled by the ``MetalCooling`` parameter, as discused below.
``GadgetCooling`` (external)
This flag (1 - on, 0 - off) turns on (when set to 1) a set of
routines that calculate cooling rates based on the assumption of a
six-species primordial gas (H, He, no H2 or D) in equilibrium, and
is valid for temperatures greater than 10,000 K. This requires the
file ``TREECOOL`` to execute. Default: 0
``MetalCooling`` (external)
This flag (0 - off, 1 - metal cooling from Glover & Jappsen 2007,
2 - Cen et al (1995), 3 - Cloudy cooling from Smith, Sigurdsson, &
Abel 2008) turns on metal cooling for runs that track
metallicity. Option 1 is valid for temperatures between 100 K and
10\ :sup:`8`\ K because it considers fine-structure line emission
from carbon, oxygen, and silicon and includes the additional metal
cooling rates from Sutherland & Dopita (1993). Option 2 is only
valid for temperatures above 10\ :sup:`4`\ K. Option 3 uses
multi-dimensional tables of heating/cooling values created with
Cloudy and optionally coupled to the ``MultiSpecies``
chemistry/cooling solver. This method is valid from 10 K to 10\
:sup:`8`\ K. See the Cloudy Cooling parameters below. Default: 0.
``MetalCoolingTable`` (internal)
This field contains the metal cooling table required for
``MetalCooling`` option 1. In the top level directory input/, there are
two files ``metal_cool.dat`` and ``metal_cool_pop3.dat`` that consider
metal cooling for solar abundance and abundances from
pair-instability supernovae, respectively. In the same directory,
one can find an IDL routine (``make_Zcool_table.pro``) that generates
these tables. Default: ``metal_cool.dat``
``MultiSpecies`` (external)
If this flag (1, 2, 3- on, 0 - off) is on, then the code follows
not just the total density, but also the ionization states of
Hydrogen and Helium. If set to 2, then a nine-species model
(including H2, H2+ and H-) will be computed, otherwise only six
species are followed (H, H+, He, He+, He++, e-). If set to 3, then
a 12 species model is followed, including D, D+ and HD. This
routine, like the last one, is based on work done by Abel, Zhang
and Anninos. Default: 0
``GadgetEquilibriumCooling`` (external)
An implementation of the ionization equilibrium cooling code used
in the GADGET code which includes both radiative cooling and a
uniform metagalactic UV background specified by the ``TREECOOL`` file
(in the ``amr_mpi/exe`` directory). When this parameter is turned on,
``MultiSpecies`` and ``RadiationFieldType`` are forced to 0 and
``RadiativeCooling`` is forced to 1.
[Not in public release version]
``PhotoelectricHeating`` (external)
If set to be 1, Gamma_pe = 5.1e-26 erg/s will be added uniformly
to the gas without any shielding (Tasker & Bryan 2008). At the
moment this is still experimental. Default: 0
``MultiMetals`` (external)
This was added so that the user could turn on or off additional
metal fields - currently there is the standard metallicity field
(Metal_Density) and two additional metal fields (Z_Field1 and
Z_Field2). Acceptable values are 1 or 0, Default: 0 (off).
.. _cloudy_cooling:
Cloudy Cooling
~~~~~~~~~~~~~~
Cloudy cooling from Smith, Sigurdsson, & Abel (2008) interpolates
over tables of precomputed cooling data. Cloudy cooling is turned
on by setting ``MetalCooling`` to 3. ``RadiativeCooling`` must also be set
to 1. Depending on the cooling data used, it can be coupled with
``MultiSpecies`` = 1, 2, or 3 so that the metal-free cooling comes from
the ``MultiSpecies`` machinery and the Cloudy tables provide only the
metal cooling. Datasets range in dimension from 1 to 5. Dim 1:
interpolate over temperature. Dim 2: density and temperature. Dim
3: density, metallicity, and temperature. Dim 4: density,
metallicity, electron fraction, and temperature. Dim 5: density,
metallicity, electron fraction, spectral strength, and temperature.
See Smith, Sigurdsson, & Abel (2008) for more information on
creating Cloudy datasets.
``CloudyCoolingGridFile`` (external)
A string specifying the path to the Cloudy cooling dataset.
``IncludeCloudyHeating`` (external)
An integer (0 or 1) specifying whether the heating rates are to be
included in the calculation of the cooling. Some Cloudy datasets
are made with the intention that only the cooling rates are to be
used. Default: 0 (off).
``CMBTemperatureFloor`` (external)
An integer (0 or 1) specifying whether a temperature floor is
created at the temperature of the cosmic microwave background
(T\ :sub:`CMB`\ = 2.72 (1 + z) K). This is accomplished in the
code by subtracting the cooling rate at T\ :sub:`CMB`\ such that
Cooling = Cooling(T) - Cooling(T\ :sub:`CMB`\ ). Default: 1 (on).
``CloudyElectronFractionFactor`` (external)
A float value to account for additional electrons contributed by
metals. This is only used with Cloudy datasets with dimension
greater than or equal to 4. The value of this factor is calculated
as the sum of (A\ :sub:`i`\ \* i) over all elements i heavier than
He, where A\ :sub:`i`\ is the solar number abundance relative to
H. For the solar abundance pattern from the latest version of
Cloudy, using all metals through Zn, this value is 9.153959e-3.
Default: 9.153959e-3.
Inline Halo Finding
~~~~~~~~~~~~~~~~~~~
Enzo can find dark matter (sub)halos on the fly with a
friends-of-friends (FOF) halo finder and a subfind method,
originally written by Volker Springel. All output files will be
written in the directory FOF/.
``InlineHaloFinder`` (external)
Set to 1 to turn on the inline halo finder. Default: 0.
``HaloFinderSubfind`` (external)
Set to 1 to find subhalos inside each dark matter halo found in the
friends-of-friends method. Default: 0.
``HaloFinderOutputParticleList`` (external)
Set to 1 to output a list of particle positions and IDs for each
(sub)halo. Written in HDF5. Default: 0.
``HaloFinderMinimumSize`` (external)
Minimum number of particles to be considered a halo. Default: 50.
``HaloFinderLinkingLength`` (external)
Linking length of particles when finding FOF groups. In units of
cell width of the finest static grid, e.g. unigrid -> root cell
width. Default: 0.1.
``HaloFinderCycleSkip`` (external)
Find halos every N\ :sup:`th`\ top-level timestep, where N is this
parameter. Not used if set to 0. Default: 3.
``HaloFinderTimestep`` (external)
Find halos every dt = (this parameter). Only evaluated at each
top-level timestep. Not used if negative. Default: -99999.0
``HaloFinderLastTime`` (internal)
Last time of a halo find. Default: 0.
Inline Python
~~~~~~~~~~~~~
``PythonSubcycleSkip`` (external)
The number of times Enzo should reach the bottom of the hierarchy
before exposing its data and calling Python. Only works with
python-yes in compile settings.
.. _StarParticleParameters:
Star Formation and Feedback Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For details on each of the different star formation methods available in Enzo see :ref:`star_particles`.
``StarParticleCreation`` (external)
This parameter is bitwise so that multiple types of star formation
routines can be used in a single simulation. For example if methods
1 and 3 are desired, the user would specify 10 (2\ :sup:`1`\ +
2\ :sup:`3`\ ), or if methods 1, 4 and 7 are wanted, this would be
146 (2\ :sup:`1`\ + 2\ :sup:`4`\ + 2\ :sup:`7`\ ). Default: 0
::
0 - Cen & Ostriker (1992)
1 - Cen & Ostriker (1992) with stocastic star formation
2 - Global Schmidt Law / Kravstov et al. (2003)
3 - Population III stars / Abel, Wise & Bryan (2007)
4 - Sink particles: Pure sink particle or star particle with wind feedback depending on
choice for HydroMethod / Wang et al. (2009)
5 - Radiative star clusters / Wise & Cen (2009)
6 - [reserved]
7 - Cen & Ostriker (1992) with no delay in formation
8 - Springel & Hernquist (2003)
9 - Massive Black Hole (MBH) particles insertion by hand / Kim et al. (2010)
10 - Population III stellar tracers
``StarParticleFeedback`` (external)
This parameter works the same way as ``StarParticleCreation`` but only
is valid for ``StarParticleCreation`` = 0, 1, 2, 7 and 8 because methods 3, 5 and 9
use the radiation transport module and ``Star_*.C`` routines to
calculate the feedback, 4 has explicit feedback and 10 does not use feedback. Default: 0.
``StarFeedbackDistRadius`` (external)
If this parameter is greater than zero, stellar feedback will be
deposited into the host cell and neighboring cells within this
radius. This results in feedback being distributed to a cube with
a side of ``StarFeedbackDistRadius+1``. It is in units of cell
widths of the finest grid which hosts the star particle. Only
implemented for ``StarFeedbackCreation`` = 0 or 1 with ``StarParticleFeedback`` = 1. (If ``StarParticleFeedback`` = 0, stellar feedback is only deposited into the cell in which the star particle lives). Default: 0.
``StarFeedbackDistCellStep`` (external)
In essence, this parameter controls the shape of the volume where
the feedback is applied, cropping the original cube. This volume
that are within ``StarFeedbackDistCellSteps`` cells from the host
cell, counted in steps in Cartesian directions, are injected with
stellar feedback. Its maximum value is ``StarFeedbackDistRadius``
* ``TopGridRank``. Only implemented for ``StarFeedbackCreation`` = 0
or 1. See :ref:`distributed_feedback` for an illustration.
Default: 0.
``StarMakerTypeIaSNe`` (external)
This parameter turns on thermal and chemical feedback from Type Ia
supernovae. The mass loss and luminosity of the supernovae are
determined from `fits of K. Nagamine
`_. The ejecta are
traced in a separate species field, ``MetalSNIa_Density``. The
metallicity of star particles that comes from this ejecta is
stored in the particle attribute ``typeia_fraction``. Can be used
with ``StarParticleCreation`` = 0, 1, 2, 5, 7, and 8. Default:
0.
``StarMakerPlanetaryNebulae`` (external)
This parameter turns on thermal and chemical feedback from
planetary nebulae. The mass loss and luminosity are taken from
the same `fits from K. Nagamine
`_. The chemical
feedback injects gas with the same metallicity as the star
particle, and the thermal feedback equates to a 10 km/s wind. The
ejecta are not stored in its own species field. Can be used
with ``StarParticleCreation`` = 0, 1, 2, 5, 7, and 8. Default: 0.
Normal Star Formation
^^^^^^^^^^^^^^^^^^^^^
The parameters below are considered in ``StarParticleCreation`` method
0, 1, 2, 7 and 8.
``StarMakerOverDensityThreshold`` (external)
The overdensity threshold in code units (for cosmological simulations, note that code units are relative to the total mean density, not
just the dark matter mean density) before star formation will be
considered. For ``StarParticleCreation`` = 7 in cosmological
simulations, however, ``StarMakerOverDensityThreshold`` should be in
particles/cc, so it is not the ratio with respect to the
``DensityUnits`` (unlike most other
star_makers). This way one correctly represents the Jeans
collapse and molecular cloud scale physics even in cosmological
simulations. Default: 100
``StarMakerSHDensityThreshold`` (external)
The critical density of gas used in Springel & Hernquist star
formation ( \\rho_{th} in the paper) used to determine the star
formation timescale in units of g cm\ :sup:`-3`\ . Only valid for ``StarParticleCreation`` = 8. Default: 7e-26.
``StarMakerMassEfficiency`` (external)
The fraction of identified baryonic mass in a cell
(Mass\*dt/t_dyn) that is converted into a star particle. Default:
1
``StarMakerMinimumMass`` (external)
The minimum mass of star particle, in solar masses. Note however,
the star maker algorithm 2 has a (default off) "stochastic" star formation
algorithm that will, in a pseudo-random fashion, allow star
formation even for very low star formation rates. It attempts to do
so (relatively successfully according to tests) in a fashion that
conserves the global average star formation rate. Default: 1e9
``StarMakerMinimumDynamicalTime`` (external)
When the star formation rate is computed, the rate is proportional
to M_baryon \* dt/max(t_dyn, t_max) where t_max is this
parameter. This effectively sets a limit on the rate of star
formation based on the idea that stars have a non-negligible
formation and life-time. The unit is years. Default: 1e6
``StarMassEjectionFraction`` (external)
The mass fraction of created stars which is returned to the gas
phase. Default: 0.25
``StarMetalYield`` (external)
The mass fraction of metals produced by each unit mass of stars
created (i.e. it is multiplied by mstar, not ejected). Default:
0.02
``StarEnergyToThermalFeedback`` (external)
The fraction of the rest-mass energy of the stars created which is
returned to the gas phase as thermal energy. Default: 1e-5
``StarEnergyToStellarUV`` (external)
The fraction of the rest-mass energy of the stars created which is
returned as UV radiation with a young star spectrum. This is used
when calculating the radiation background. Default: 3e-6
``StarEnergyToQuasarUV`` (external)
The fraction of the rest-mass energy of the stars created which is
returned as UV radiation with a quasar spectrum. This is used when
calculating the radiation background. Default: 5e-6
Population III Star Formation
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The parameters below are considered in ``StarParticleCreation`` method 3.
``PopIIIStarMass`` (external)
Stellar mass of Population III stars created in
``StarParticleCreation`` method 3. Units of solar masses. The
luminosities and supernova energies are calculated from Schaerer
(2002) and Heger & Woosley (2002), respectively.
``PopIIIBlackHoles`` (external)
Set to 1 to create black hole particles that radiate in X-rays for
stars that do not go supernova (< 140 solar masses and > 260 solar
masses). Default: 0.
``PopIIIBHLuminosityEfficiency`` (internal)
The radiative efficiency in which the black holes convert accretion
to luminosity. Default: 0.1.
``PopIIIOverDensityThreshold`` (internal)
The overdensity threshold (relative to the total mean density)
before Pop III star formation will be considered. Default: 1e6.
``PopIIIH2CriticalFraction`` (internal)
The H_2 fraction threshold before Pop III star formation will be
considered. Default: 5e-4.
``PopIIIMetalCriticalFraction`` (internal)
The metallicity threshold (relative to gas density, not solar)
before Pop III star formation will be considered. Note: this should
be changed to be relative to solar! Default: 1e-4.
``PopIIISupernovaRadius`` (internal)
If the Population III star will go supernova (140 1. If
``MultiSpecies`` > 1 and this option is off, the Lyman-Werner radiation
field will be calculated with ray tracing. Default: 1.
``RadiativeTransferSplitPhotonPackage`` (internal)
Once photons are past this radius, they can no longer split. In
units of kpc. If this value is negative (by default), photons can
always split. Default: ``FLOAT_UNDEFINED``.
``RadiativeTransferPhotonEscapeRadius`` (internal)
The number of photons that pass this distance from its source are
summed into the global variable ``EscapedPhotonCount[]``. This variable
also keeps track of the number of photons passing this radius
multiplied by 0.5, 1, and 2. Units are in kpc. Not used if set to
0. Default: 0.
``RadiativeTransferInterpolateField`` (obsolete)
A failed experiment in which we evaluate the density at the
midpoint of the ray segment in each cell to calculate the optical
depth. To interpolate, we need to calculate the vertex interpolated
density fields. Default: 0.
``RadiativeTransferSourceClustering`` (internal)
Set to 1 to turn on ray merging from combined virtual sources on a
binary tree. Default: 0.
``RadiativeTransferPhotonMergeRadius`` (internal)
The radius at which the rays will merge from their SuperSource,
which is the luminosity weighted center of two sources. This radius
is in units of the separation of two sources associated with one
SuperSource. If set too small, there will be angular artifacts in
the radiation field. Default: 2.5
``RadiativeTransferTimestepVelocityLimit`` (external)
Limits the radiative transfer timestep to a minimum value that is
determined by the cell width at the finest level divided by this
velocity. Units are in km/s. Default: 100.
``RadiativeTransferPeriodicBoundary`` (external)
Set to 1 to turn on periodic boundary conditions for photon
packages. Default: 0.
``RadiativeTransferTraceSpectrum`` (external)
reserved for experimentation. Default: 0.
``RadiativeTransferTraceSpectrumTable`` (external)
reserved for experimentation. Default: ``spectrum_table.dat``
``RadiationXRaySecondaryIon`` (external)
Set to 1 to turn on secondary ionizations and reduce heating from
X-ray radiation (Shull & van Steenberg 1985). Currently only BH and
MBH particles emit X-rays. Default: 0.
``RadiationXRayComptonHeating`` (external)
Set to 1 to turn on Compton heating on electrons from X-ray
radiation (Ciotti & Ostriker 2001). Currently only BH and MBH
particles emit X-rays. Default: 0.
Radiative Transfer (FLD) Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
``RadiativeTransferFLD`` (external)
Set to 2 to turn on the fld-based radiation solvers following Reynolds,
Hayes, Paschos & Norman, 2009. Note that you also have to compile
the source using ``make photon-yes`` and a ``make
hypre-yes``. Note that if FLD is turned on, it will force
``RadiativeCooling = 0``, ``GadgetEquilibriumCooling = 0``, and
``RadiationFieldType = 0`` to prevent conflicts. Default: 0.
``ImplicitProblem`` (external)
Set to 1 to turn on the implicit FLD solver, or 3 to turn on the
split FLD solver. Default: 0.
``RadHydroParamfile`` (external)
Names the (possibly-different) input parameter file containing
solver options for the FLD-based solvers. These are described in
the relevant User Guides, located in ``doc/implicit_fld`` and
``doc/split_fld``. Default: NULL.
``RadiativeTransfer`` (external)
Set to 0 to avoid conflicts with the ray tracing solver above.
Default: 0.
``RadiativeTransferFLDCallOnLevel`` (reserved)
The level in the static AMR hierarchy where the unigrid FLD solver
should be called. Currently only works for 0 (the root grid).
Default: 0.
``RadiativeTransferOpticallyThinH2`` (external)
Set to 0 to avoid conflicts with the built-in optically-thin H_2
dissociating field from the ray-tracing solver. Default: 1.
Radiative Transfer (FLD) Implicit Solver Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
These parameters should be placed within the file named in
``RadHydroParamfile`` in the main parameter file. All are described in
detail in the User Guide in ``doc/implicit_fld``.
``RadHydroESpectrum`` (external)
Type of assumed radiation spectrum for radiation field, Default: 1.
::
-1 - monochromatic spectrum at frequency h nu_{HI} = 13.6 eV
0 - power law spectrum, (nu / nu_{HI} )^(-1.5)
1 - T = 1e5 blackbody spectrum
``RadHydroChemistry`` (external)
Use of hydrogen chemistry in ionization model, set to 1 to turn on
the hydrogen chemistry, 0 otherwise. Default: 1.
``RadHydroHFraction`` (external)
Fraction of baryonic matter comprised of hydrogen. Default: 1.0.
``RadHydroModel`` (external)
Determines which set of equations to use within the solver.
Default: 1.
::
1 - chemistry-dependent model, with case-B hydrogen II recombination coefficient.
2 - chemistry-dependent model, with case-A hydrogen II recombination coefficient.
4 - chemistry-dependent model, with case-A hydrogen II
recombination coefficient, but assumes an isothermal gas energy.
10 - no chemistry, instead uses a model of local thermodynamic
equilibrium to couple radiation to gas energy.
``RadHydroMaxDt`` (external)
maximum time step to use in the FLD solver. Default: 1e20 (no
limit).
``RadHydroMinDt`` (external)
minimum time step to use in the FLD solver. Default: 0.0 (no
limit).
``RadHydroInitDt`` (external)
initial time step to use in the FLD solver. Default: 1e20 (uses
hydro time step).
``RadHydroDtNorm`` (external)
type of p-norm to use in estimating time-accuracy for predicting
next time step. Default: 2.0.
::
0 - use the max-norm.
>0 - use the specified p-norm.
<0 - illegal.
``RadHydroDtRadFac`` (external)
Desired time accuracy tolerance for the radiation field. Default:
1e20 (unused).
``RadHydroDtGasFac`` (external)
Desired time accuracy tolerance for the gas energy field. Default:
1e20 (unused).
``RadHydroDtChemFac`` (external)
Desired time accuracy tolerance for the hydrogen I number density.
Default: 1e20 (unused).
``RadiationScaling`` (external)
Scaling factor for the radiation field, in case standard
non-dimensionalization fails. Default: 1.0.
``EnergyCorrectionScaling`` (external)
Scaling factor for the gas energy correction, in case standard
non-dimensionalization fails. Default: 1.0.
``ChemistryScaling`` (external)
Scaling factor for the hydrogen I number density, in case standard
non-dimensionalization fails. Default: 1.0.
``RadiationBoundaryX0Faces`` (external)
Boundary condition types to use on the x0 faces of the radiation
field. Default: [0 0].
::
0 - Periodic.
1 - Dirichlet.
2 - Neumann.
``RadiationBoundaryX1Faces`` (external)
Boundary condition types to use on the x1 faces of the radiation
field. Default: [0 0].
``RadiationBoundaryX2Faces`` (external)
Boundary condition types to use on the x2 faces of the radiation
field. Default: [0 0].
``RadHydroLimiterType`` (external)
Type of flux limiter to use in the FLD approximation. Default: 4.
::
0 - original Levermore-Pomraning limiter, à la Levermore & Pomraning, 1981 and Levermore, 1984.
1 - rational approximation to LP limiter.
2 - new approximation to LP limiter (to reduce floating-point cancellation error).
3 - no limiter.
4 - ZEUS limiter (limiter 2, but with no "effective albedo").
``RadHydroTheta`` (external)
Time-discretization parameter to use, 0 gives explicit Euler, 1
gives implicit Euler, 0.5 gives trapezoidal. Default: 1.0.
``RadHydroAnalyticChem`` (external)
Type of time approximation to use on gas energy and chemistry
equations. Default: 1 (if possible for model).
::
0 - use a standard theta-method.
1 - use an implicit quasi-steady state (IQSS) approximation.
``RadHydroInitialGuess`` (external)
Type of algorithm to use in computing the initial guess for the
time-evolved solution. Default: 0.
::
0 - use the solution from the previous time step (safest).
1 - use explicit Euler with only spatially-local physics (heating & cooling).
2 - use explicit Euler with all physics.
5 - use an analytic predictor based on IQSS approximation of
spatially-local physics.
``RadHydroNewtTolerance`` (external)
Desired accuracy for solution to satisfy nonlinear residual
(measured in the RMS norm). Default: 1e-6.
``RadHydroNewtIters`` (external)
Allowed number of Inexact Newton iterations to achieve tolerance
before returning with FAIL. Default: 20.
``RadHydroINConst`` (external)
Inexact Newton constant used in specifying tolerances for inner
linear solver. Default: 1e-8.
``RadHydroMaxMGIters`` (external)
Allowed number of iterations for the inner linear solver (geometric
multigrid). Default: 50.
``RadHydroMGRelaxType`` (external)
Relaxation method used by the multigrid solver. Default: 1.
::
1 - Jacobi.
2 - Weighted Jacobi.
3 - Red/Black Gauss-Seidel (symmetric).
4 - Red/Black Gauss-Seidel (non-symmetric).
``RadHydroMGPreRelax`` (external)
Number of pre-relaxation sweeps used by the multigrid solver.
Default: 1.
``RadHydroMGPostRelax`` (external)
Number of post-relaxation sweeps used by the multigrid solver.
Default: 1.
``EnergyOpacityC0``, ``EnergyOpacityC1``, ``EnergyOpacityC2``, ``EnergyOpacityC3``, ``EnergyOpacityC4`` (external)
Parameters used in defining the energy-mean opacity used with
``RadHydroModel`` 10. Default: [1 1 0 1 0].
``PlanckOpacityC0``, ``PlanckOpacityC1``, ``PlanckOpacityC2``, ``PlanckOpacityC3``, ``PlanckOpacityC4`` (external)
Parameters used in defining the Planck-mean opacity used with
``RadHydroModel`` 10. Default: [1 1 0 1 0].
Radiative Transfer (FLD) Split Solver Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
These parameters should be placed within the file named in
``RadHydroParamfile`` in the main parameter file. All are described in
detail in the User Guide in ``doc/split_fld``.
``RadHydroESpectrum`` (external)
Type of assumed radiation spectrum for radiation field, Default: 1.
::
-1 - monochromatic spectrum at frequency h nu_{HI}= 13.6 eV
0 - power law spectrum, (nu / nu_{HI})^(-1.5)
1 - T=1e5 blackbody spectrum
``RadHydroChemistry`` (external)
Use of hydrogen chemistry in ionization model, set to 1 to turn on
the hydrogen chemistry, 0 otherwise. Default: 1.
``RadHydroHFraction`` (external)
Fraction of baryonic matter comprised of hydrogen. Default: 1.0.
``RadHydroModel`` (external)
Determines which set of equations to use within the solver.
Default: 1.
::
1 - chemistry-dependent model, with case-B hydrogen II recombination
coefficient.
4 - chemistry-dependent model, with case-A hydrogen II recombination
coefficient, but assumes an isothermal gas energy.
10 - no chemistry, instead uses a model of local thermodynamic
equilibrium to couple radiation to gas energy.
``RadHydroMaxDt`` (external)
maximum time step to use in the FLD solver. Default: 1e20 (no
limit).
``RadHydroMinDt`` (external)
minimum time step to use in the FLD solver. Default: 0.0 (no
limit).
``RadHydroInitDt`` (external)
initial time step to use in the FLD solver. Default: 1e20 (uses
hydro time step).
``RadHydroDtNorm`` (external)
type of p-norm to use in estimating time-accuracy for predicting
next time step. Default: 2.0.
::
0 - use the max-norm.
>0 - use the specified p-norm.
<0 - illegal.
``RadHydroDtRadFac`` (external)
Desired time accuracy tolerance for the radiation field. Default:
1e20 (unused).
``RadHydroDtGasFac`` (external)
Desired time accuracy tolerance for the gas energy field. Default:
1e20 (unused).
``RadHydroDtChemFac`` (external)
Desired time accuracy tolerance for the hydrogen I number density.
Default: 1e20 (unused).
``RadiationScaling`` (external)
Scaling factor for the radiation field, in case standard
non-dimensionalization fails. Default: 1.0.
``EnergyCorrectionScaling`` (external)
Scaling factor for the gas energy correction, in case standard
non-dimensionalization fails. Default: 1.0.
``ChemistryScaling`` (external)
Scaling factor for the hydrogen I number density, in case standard
non-dimensionalization fails. Default: 1.0.
``RadiationBoundaryX0Faces`` (external)
Boundary condition types to use on the x0 faces of the radiation
field. Default: [0 0].
::
0 - Periodic.
1 - Dirichlet.
2 - Neumann.
``RadiationBoundaryX1Faces`` (external)
Boundary condition types to use on the x1 faces of the radiation
field. Default: [0 0].
``RadiationBoundaryX2Faces`` (external)
Boundary condition types to use on the x2 faces of the radiation
field. Default: [0 0].
``RadHydroTheta`` (external)
Time-discretization parameter to use, 0 gives explicit Euler, 1
gives implicit Euler, 0.5 gives trapezoidal. Default: 1.0.
``RadHydroSolTolerance`` (external)
Desired accuracy for solution to satisfy linear residual (measured
in the 2-norm). Default: 1e-8.
``RadHydroMaxMGIters`` (external)
Allowed number of iterations for the inner linear solver (geometric
multigrid). Default: 50.
``RadHydroMGRelaxType`` (external)
Relaxation method used by the multigrid solver. Default: 1.
::
Jacobi.
Weighted Jacobi.
Red/Black Gauss-Seidel (symmetric).
Red/Black Gauss-Seidel (non-symmetric).
``RadHydroMGPreRelax`` (external)
Number of pre-relaxation sweeps used by the multigrid solver.
Default: 1.
``RadHydroMGPostRelax`` (external)
Number of post-relaxation sweeps used by the multigrid solver.
Default: 1.
``EnergyOpacityC0``, ``EnergyOpacityC1``, ``EnergyOpacityC2`` (external)
Parameters used in defining the energy-mean opacity used with
RadHydroModel 10. Default: [1 1 0].
Massive Black Hole Physics Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Following parameters are for the accretion and feedback from the
massive black hole particle (``PARTICLE_TYPE_MBH``). More details
will soon be described in Kim et al. (2010).
Accretion Physics
^^^^^^^^^^^^^^^^^
``MBHAccretion`` (external)
Set to 1 to turn on accretion based on the Eddington-limited
spherical Bondi-Hoyle formula (Bondi 1952). Set to 2 to turn on
accretion based on the Bondi-Hoyle formula but with fixed
temperature defined below. Set to 3 to turn on accretion with a
fixed rate defined below. Set to 4 to to turn on accretion based on
the Eddington-limited spherical Bondi-Hoyle formula, but without
v_rel in the denominator. Set to 5 to turn on accretion based on
Krumholz et al.(2006) which takes vorticity into account. Set to 6
to turn on alpha disk formalism based on DeBuhr et al.(2010).
7 and 8 are still failed experiment. Add 10 to each of these options
(i.e. 11, 12, 13, 14) to ignore the Eddington limit. See
``Star_CalculateMassAccretion.C``. Default: 0 (FALSE)
``MBHAccretionRadius`` (external)
This is the radius (in pc) of a gas sphere from which the accreting
mass is subtracted out at every timestep. Instead, you may want to
try set this parameter to -1, in which case an approximate Bondi
radius is calculated and used (from ``DEFAULT_MU`` and
``MBHAccretionFixedTemperature``). If set to -N, it will use N\*(Bondi
radius). See ``CalculateSubtractionParameters.C``. Default: 50.0
``MBHAccretingMassRatio`` (external)
There are three different scenarios you can utilize this parameter.
(1) In principle this parameter is a nondimensional factor
multiplied to the Bondi-Hoyle accretion rate; so 1.0 should give
the plain Bondi rate. (2) However, if the Bondi radius is resolved
around the MBH, the local density used to calculate Mdot can be
higher than what was supposed to be used (density at the Bondi
radius!), resulting in the overestimation of Mdot. 0.0 <
``MBHAccretingMassRatio`` < 1.0 can be used to fix this. (3) Or, one
might try using the density profile of R\ :sup:`-1.5`\ to estimate
the density at the Bondi radius, which is utilized when
``MBHAccretingMassRatio`` is set to -1. See
``Star_CalculateMassAccretion.C``. Default: 1.0
``MBHAccretionFixedTemperature`` (external)
This parameter (in K) is used when ``MBHAccretion = 2``. A fixed gas
temperature that goes into the Bondi-Hoyle accretion rate
estimation formula. Default: 3e5
``MBHAccretionFixedRate`` (external)
This parameter (in Msun/yr) is used when ``MBHAccretion = 3``. Default:
1e-3
``MBHTurnOffStarFormation`` (external)
Set to 1 to turn off star formation (only for ``StarParicleCreation``
method 7) in the cells where MBH particles reside. Default: 0
(FALSE)
``MBHCombineRadius`` (external)
The distance (in pc) between two MBH particles in which two
energetically-bound MBH particles merge to form one particle.
Default: 50.0
``MBHMinDynamicalTime`` (external)
Minimum dynamical time (in yr) for a MBH particle. Default: 1e7
``MBHMinimumMass`` (external)
Minimum mass (in Msun) for a MBH particle. Default: 1e3
Feedback Physics
^^^^^^^^^^^^^^^^
``MBHFeedback`` (external)
Set to 1 to turn on thermal feedback of MBH particles (``MBH_THERMAL``
- not fully tested). Set to 2 to turn on mechanical feedback of MBH
particles (``MBH_JETS``, bipolar jets along the total angular momentum
of gas accreted onto the MBH particle so far). Set to 3 to turn on
another version of mechanical feedback of MBH particles (``MBH_JETS``,
always directed along z-axis). Set to 4 to turn on experimental version of
mechanical feedback (`MBH_JETS`, bipolar jets along the total angular
momentum of gas accreted onto the MBH particle so far + 10 degree random
noise). Set to 5 to turn on experimental version of mechanical feedback
(``MBH_JETS``, launched at random direction). Note that, even when this
parameter is set to 0, MBH particles still can be radiation sources
if ``RadiativeTransfer`` is on. See ``Grid_AddFeedbackSphere.C``.
Default: 0 (FALSE)
::
``RadiativeTransfer = 0`` & ``MBHFeedback = 0`` : no feedback at all
``RadiativeTransfer = 0`` & ``MBHFeedback = 1`` : purely thermal feedback
``RadiativeTransfer = 0`` & ``MBHFeedback = 2`` : purely mechanical feedback
``RadiativeTransfer = 1`` & ``MBHFeedback = 0`` : purely radiative feedback
``RadiativeTransfer = 1`` & ``MBHFeedback = 2`` : radiative and
mechanical feedback combined (one has to change the following
``MBHFeedbackRadiativeEfficiency`` parameter accordingly, say from 0.1
to 0.05, to keep the same total energy across different modes of
feedback)
``MBHFeedbackRadiativeEfficiency`` (external)
The radiative efficiency of a black hole. 10% is the widely
accepted value for the conversion rate from the rest-mass energy of
the accreting material to the feedback energy, at the innermost
stable orbit of a non-spinning Schwarzschild black hole (Shakura &
Sunyaev 1973, Booth & Schaye 2009). Default: 0.1
``MBHFeedbackEnergyCoupling`` (external)
The fraction of feedback energy that is thermodynamically (for
``MBH_THERMAL``) or mechanically (for ``MBH_JETS``) coupled to the gas.
0.05 is widely used for thermal feedback (Springel et al. 2005, Di
Matteo et al. 2005), whereas 0.0001 or less is recommended for
mechanical feedback depending on the resolution of the simulation
(Ciotti et al. 2009). Default: 0.05
``MBHFeedbackMassEjectionFraction`` (external)
The fraction of accreting mass that is returning to the gas phase.
For either ``MBH_THERMAL`` or ``MBH_JETS``. Default: 0.1
``MBHFeedbackMetalYield`` (external)
The mass fraction of metal in the ejected mass. Default: 0.02
``MBHFeedbackThermalRadius`` (external)
The radius (in pc) of a sphere in which the energy from
``MBH_THERMAL`` feedback is deposited. If set to a negative value, the
radius of a sphere gets bigger in a way that the sphere encloses
the constant mass (=
4/3\*pi\*(-``MBHFeedbackThermalRadius``)\ :sup:`3`\ Msun). The latter
is at the moment very experimental; see ``Star_FindFeedbackSphere.C``.
Default: 50.0
``MBHFeedbackJetsThresholdMass`` (external)
The bipolar jets by ``MBH_JETS`` feedback are injected every time the
accumulated ejecta mass surpasses ``MBHFeedbackJetsThresholdMass`` (in
Msun). Although continuously injecting jets into the gas cells
might sound great, unless the gas cells around the MBH are resolved
down to Mdot, the jets make little or no dynamical impact on the
surrounding gas. By imposing ``MBHFeedbackJetsThresholdMass``, the jets
from MBH particles are rendered intermittent, yet dynamically
important. Default: 10.0
``MBHParticleIO`` (external)
Set to 1 to print out basic information about MBH particles. Will
be automatically turned on if ``MBHFeedback`` is set to 2 or 3.
Default: 0 (FALSE)
``MBHParticleIOFilename`` (external)
The name of the file used for the parameter above. Default:
``mbh_particle_io.dat``
Conduction
~~~~~~~~~~~~~~~~~~~~~~
Isotropic and anisotropic thermal conduction are implemented using the
method of Parrish and Stone: namely, using an explicit, forward
time-centered algorithm. In the anisotropic conduction, heat can only
conduct along magnetic field lines. One can turn on the two types of
conduction independently, since there are situations where one might
want to use both. The Spitzer fraction can be also set
independently for the isotropic and anisotropic conduction.
``IsotropicConduction`` (external)
Turns on isotropic thermal conduction using Spitzer conduction. Default: 0 (FALSE)
``AnisotropicConduction`` (external)
Turns on anisotropic thermal conduction using Spitzer conduction.
Can only be used if MHD is turned on (``HydroMethod`` = 4).
Default: 0 (FALSE)
``IsotropicConductionSpitzerFraction`` (external)
Prefactor that goes in front of the isotropic Spitzer conduction
coefficient. Should be a value between 0 and 1.
Default: 1.0
``AnisotropicConductionSpitzerFraction`` (external)
Prefactor that goes in front of the anisotropic Spitzer conduction
coefficient. Should be a value between 0 and 1.
Default: 1.0
``ConductionCourantSafetyNumber`` (external)
This is a prefactor that controls the stability of the conduction
algorithm. In its current explicit formulation, it must be set to
a value of 0.5 or less.
Default: 0.5
Shock Finding Parameters
~~~~~~~~~~~~~~~~~~~~~~~~
For details on shock finding in Enzo see :ref:`shock_finding`.
``ShockMethod`` (external)
This parameter controls the use and type of shock finding. Default: 0
::
0 - Off
1 - Temperature Dimensionally Unsplit Jumps
2 - Temperature Dimensionally Split Jumps
1 - Velocity Dimensionally Unsplit Jumps
2 - Velocity Dimensionally Split Jumps
``ShockTemperatureFloor`` (external)
When calculating the mach number using temperature jumps, set the
temperature floor in the calculation to this value.
``StorePreShockFields`` (external)
Optionally store the Pre-shock Density and Temperature during data output.
.. _testproblem_param:
Test Problem Parameters
-----------------------
.. _shocktube_param:
Shock Tube (1: unigrid and AMR)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Riemann problem or arbitrary discontinuity breakup problem. The
discontinuity initially separates two arbitrary constant states:
Left and Right. Default values correspond to the so called Sod
Shock Tube setup (test 1.1). A table below contains a series of
recommended 1D tests for hydrodynamic method, specifically designed
to test the performance of the Riemann solver, the treatment of
shock waves, contact discontinuities, and rarefaction waves in a
variety of situations (Toro 1999, p. 129).
::
Test LeftDensity LeftVelocity LeftPressure RightDensity RightVelocity RightPressure
1.1 1.0 0.0 1.0 0.125 0.0 0.1
1.2 1.0 -2.0 0.4 1.0 2.0 0.4
1.3 1.0 0.0 1000.0 1.0 0.0 0.01
1.4 1.0 0.0 0.01 1.0 0.0 100.0
1.5 5.99924 19.5975 460.894 5.99242 -6.19633 46.0950
``ShockTubeBoundary`` (external)
Discontinuity position. Default: 0.5
``ShockTubeDirection`` (external)
Discontinuity orientation. Type: integer. Default: 0 (shock(s) will
propagate in x-direction)
``ShockTubeLeftDensity``, ``ShockTubeRightDensity`` (external)
The initial gas density to the left and to the right of the
discontinuity. Default: 1.0 and 0.125, respectively
``ShockTubeLeftVelocity``, ``ShockTubeRightVelocity`` (external)
The same as above but for the velocity component in
``ShockTubeDirection``. Default: 0.0, 0.0
``ShockTubeLeftPressure``, ``ShockTubeRightPressure`` (external)
The same as above but for pressure. Default: 1.0, 0.1
.. _wavepool_param:
Wave Pool (2)
~~~~~~~~~~~~~
Wave Pool sets up a simulation with a 1D sinusoidal wave entering
from the left boundary. The initial active region is uniform and
the wave is entered via inflow boundary conditions.
``WavePoolAmplitude`` (external)
The amplitude of the wave. Default: 0.01 - a linear wave.
``WavePoolAngle`` (external)
Direction of wave propagation with respect to x-axis. Default: 0.0
``WavePoolDensity`` (external)
Uniform gas density in the pool. Default: 1.0
``WavePoolNumberOfWaves`` (external)
The test initialization will work for one wave only. Default: 1
``WavePoolPressure`` (external)
Uniform gas pressure in the pool. Default: 1.0
``WavePoolSubgridLeft``, ``WavePoolSubgridRight`` (external)
Start and end positions of the subgrid. Default: 0.0 and 0.0 (no
subgrids)
``WavePoolVelocity1(2,3)`` (external)
x-,y-, and z-velocities. Default: 0.0 (for all)
``WavePoolWavelength`` (external)
The wavelength. Default: 0.1 (one-tenth of the box)
.. _shockpool_param:
Shock Pool (3: unigrid 2D, AMR 2D and unigrid 3D)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The Shock Pool test sets up a system which introduces a shock from
the left boundary. The initial active region is uniform, and the
shock wave enters via inflow boundary conditions. 2D and 3D
versions available. (D. Mihalas & B.W. Mihalas, Foundations of
Radiation Hydrodynamics, 1984, p. 236, eq. 56-40.)
``ShockPoolAngle`` (external)
Direction of the shock wave propagation with respect to x-axis.
Default: 0.0
``ShockPoolDensity`` (external)
Uniform gas density in the preshock region. Default: 1.0
``ShockPoolPressure`` (external)
Uniform gas pressure in the preshock region. Default: 1.0
``ShockPoolMachNumber`` (external)
The ratio of the shock velocity and the preshock sound speed.
Default: 2.0
``ShockPoolSubgridLeft``, ``ShockPoolSubgridRight`` (external)
Start and end positions of the subgrid. Default: 0.0 and 0.0 (no
subgrids)
``ShockPoolVelocity1(2,3)`` (external)
Preshock gas velocity (the Mach number definition above assumes a
zero velocity in the laboratory reference frame. Default: 0.0 (for
all components)
.. _doublemach_param:
Double Mach Reflection (4)
~~~~~~~~~~~~~~~~~~~~~~~~~~
A test for double Mach reflection of a strong shock (Woodward &
Colella 1984). Most of the parameters are "hardwired": d0 = 8.0, e0
= 291.25, u0 = 8.25\*sqrt(3.0)/2.0, v0 = -8.25\*0.5, w0 = 0.0
``DoubleMachSubgridLeft`` (external)
Start position of the subgrid. Default: 0.0
``DoubleMachSubgridRight`` (external)
End positions of the subgrid. Default: 0.0
.. _shockinabox_param:
Shock in a Box (5)
~~~~~~~~~~~~~~~~~~
A stationary shock front in a static 3D subgrid (Anninos et al.
1994). Initialization is done as in the Shock Tube test.
``ShockInABoxBoundary`` (external)
Position of the shock. Default: 0.5
``ShockInABoxLeftDensity``, ``ShockInABoxRightDensity`` (external)
Densities to the right and to the left of the shock front. Default:
``dL=1.0`` and ``dR = dL*((Gamma+1)*m^2)/((Gamma-1)*m^2 + 2)``, where
``m=2.0`` and ``speed=0.9*sqrt(Gamma*pL/dL)*m``.
``ShockInABoxLeftVelocity``, ``ShockInABoxRightVelocity`` (external)
Velocities to the right and to the left of the shock front.
Default: ``vL=shockspeed`` and
``vR=shockspeed-m*sqrt(Gamma*pL/dL)*(1-dL/dR)``, where ``m=2.0``,
``shockspeed=0.9*sqrt(Gamma*pL/dL)*m``.
``ShockInABoxLeftPressure``, ``ShockInABoxRightPressure`` (external)
Pressures to the Right and to the Left of the shock
front. Default: pL=1.0 and pR=pL*(2.0*Gamma*m^2 -
(Gamma-1))/(Gamma+1), where m=2.0.
``ShockInABoxSubgridLeft``, ``ShockInABoxSubgridRight`` (external)
Start and end positions of the subgrid. Default: 0.0 (for both)
.. _rotatingcylinder_param:
Rotating Cylinder (10)
~~~~~~~~~~~~~~~~~~~~~~
A test for the angular momentum conservation of a collapsing
cylinder of gas in an AMR simulation. Written by Brian O'Shea
(`oshea@msu.edu `_).
``RotatingCylinderOverdensity`` (external)
Density of the rotating cylinder with respect to the
background. Default: 20.0
``RotatingCylinderSubgridLeft``, ``RotatingCylinderSubgridRight`` (external)
This pair of floating point numbers creates a subgrid region at the
beginning of the simulation that will be refined to
``MaximumRefinementLevel``. It should probably encompass the whole
cylinder. Positions are in units of the box, and it always creates
a cube. No default value (meaning off).
``RotatingCylinderLambda`` (external)
Angular momentum of the cylinder as a dimensionless quantity. This
is identical to the angular momentum parameter lambda that is
commonly used to describe cosmological halos. A value of 0.0 is
non-rotating, and 1.0 means that the gas is already approximately
rotating at the Keplerian value. Default: 0.05
``RotatingCylinderTotalEnergy`` (external)
Sets the default gas energy of the ambient medium, in Enzo internal
units. Default: 1.0
``RotatingCylinderRadius`` (external)
Radius of the rotating cylinder in units of the box size. Note that
the height of the cylinder is equal to the diameter. Default: 0.3
``RotatingCylinderCenterPosition`` (external)
Position of the center of the cylinder as a vector of floats.
Default: (0.5, 0.5, 0.5)
.. _radiatingshock_param:
Radiating Shock (11)
~~~~~~~~~~~~~~~~~~~~
This is a test problem similar to the Sedov test problem documented
elsewhere, but with radiative cooling turned on (and the ability to
use ``MultiSpecies`` and all other forms of cooling). The main
difference is that there are quite a few extras thrown in,
including the ability to initialize with random density
fluctuations outside of the explosion region, use a Sedov blast
wave instead of just thermal energy, and some other goodies (as
documented below).
``RadiatingShockInnerDensity`` (external)
Density inside the energy deposition area (Enzo internal units).
Default: 1.0
``RadiatingShockOuterDensity`` (external)
Density outside the energy deposition area (Enzo internal units).
Default: 1.0
``RadiatingShockPressure`` (external)
Pressure outside the energy deposition area (Enzo internal units).
Default: 1.0e-5
``RadiatingShockEnergy`` (external)
Total energy deposited (in units of 1e51 ergs). Default: 1.0
``RadiatingShockSubgridLeft``, ``RadiatingShockSubgridRight`` (external)
Pair of floats that defines the edges of the region where the
initial conditions are refined to MaximumRefinementLevel. No
default value.
``RadiatingShockUseDensityFluctuation`` (external)
Initialize external medium with random density fluctuations.
Default: 0
``RadiatingShockRandomSeed`` (external)
Seed for random number geneator (currently using Mersenne Twister).
Default: 123456789
``RadiatingShockDensityFluctuationLevel`` (external)
Maximum fractional fluctuation in the density level. Default: 0.1
``RadiatingShockInitializeWithKE`` (external)
Initializes the simulation with some initial kinetic energy if
turned on (0 - off, 1 - on). Whether this is a simple sawtooth or a
Sedov profile is controlled by the parameter
``RadiatingShockUseSedovProfile``. Default: 0
``RadiatingShockUseSedovProfile`` (external)
If set to 1, initializes simulation with a Sedov blast wave profile
(thermal and kinetic energy components). If this is set to 1, it
overrides all other kinetic energy-related parameters. Default: 0
``RadiatingShockSedovBlastRadius`` (external)
Maximum radius of the Sedov blast, in units of the box size.
Default: 0.05
``RadiatingShockKineticEnergyFraction`` (external)
Fraction of the total supernova energy that is deposited as kinetic
energy. This only is used if ``RadiatingShockInitializeWithKE`` is set
to 1. Default: 0.0
``RadiatingShockCenterPosition`` (external)
Vector of floats that defines the center of the explosion. Default:
(0.5, 0.5, 0.5)
``RadiatingShockSpreadOverNumZones`` (external)
Number of cells that the shock is spread over. This corresponds to
a radius of approximately N \* dx, where N is the number of cells
and dx is the resolution of the highest level of refinement. This
does not have to be an integer value. Default: 3.5
.. _freeexpansion_param:
Free Expansion (12)
~~~~~~~~~~~~~~~~~~~
This test sets up a blast wave in the free expansion stage. There
is only kinetic energy in the sphere with the radial velocity
proportional to radius. If let evolve for long enough, the problem
should turn into a Sedov-Taylor blast wave.
``FreeExpansionFullBox`` (external)
Set to 0 to have the blast wave start at the origin with reflecting
boundaries. Set to 1 to center the problem at the domain center
with periodic boundaries. Default: 0
``FreeExpansionMass`` (external)
Mass of the ejecta in the blast wave in solar masses. Default: 1
``FreeExpansionRadius`` (external)
Initial radius of the blast wave. Default: 0.1
``FreeExpansionDensity`` (external)
Ambient density of the problem. Default: 1
``FreeExpansionEnergy`` (external)
Total energy of the blast wave in ergs. Default: 1e51
``FreeExpansionMaxVelocity`` (external)
Maximum initial velocity of the blast wave (at the outer radius).
If not set, a proper value is calculated using the formula in
Draine & Woods (1991). Default: ``FLOAT_UNDEFINED``
``FreeExpansionTemperature`` (external)
Ambient temperature of the problem in K. Default: 100
``FreeExapnsionBField`` (external)
Initial uniform magnetic field. Default: 0 0 0
``FreeExpansionVelocity`` (external)
Initial velocity of the ambient medium. Default: 0 0 0
``FreeExpansionSubgridLeft`` (external)
Leftmost edge of the region to set the initial refinement. Default: 0
``FreeExpansionSubgridRight`` (external)
Rightmost edge of the region to set the initial refinement.
Default: 0
.. _zeldovichpancake_param:
Zeldovich Pancake (20)
~~~~~~~~~~~~~~~~~~~~~~
A test for gas dynamics, expansion terms and self-gravity in both
linear and non-linear regimes [Bryan thesis (1996),
Sect. 3.3.4-3.3.5; Norman & Bryan (1998), Sect. 4]
``ZeldovichPancakeCentralOffset`` (external)
Offset of the pancake plane. Default: 0.0 (no offset)
``ZeldovichPancakeCollapseRedshift`` (external)
A free parameter which determines the epoch of caustic formation.
Default: 1.0
``ZeldovichPancakeDirection`` (external)
Orientation of the pancake. Type: integer. Default: 0 (along the
x-axis)
``ZeldovichPancakeInitialTemperature`` (external)
Initial gas temperature. Units: degrees Kelvin. Default: 100
``ZeldovichPancakeOmegaBaryonNow`` (external)
Omega Baryon at redshift z=0; standard setting. Default: 1.0
``ZeldovichPancakeOmegaCDMNow`` (external)
Omega CDM at redshift z=0. Default: 0 (assumes no dark matter)
.. _pressurelesscollapse_param:
Pressureless Collapse (21)
~~~~~~~~~~~~~~~~~~~~~~~~~~
An 1D AMR test for the gravity solver and advection routines: the
two-sided one-dimensional collapse of a homogeneous plane parallel
cloud in Cartesian coordinates. Isolated boundary conditions.
Gravitational constant G=1; free fall time 0.399. The expansion
terms are not used in this test. (Bryan thesis 1996, Sect. 3.3.1).
``PressurelessCollapseDirection`` (external)
Coordinate direction. Default: 0 (along the x-axis).
``PressurelessCollapseInitialDensity`` (external)
Initial density (the fluid starts at rest). Default: 1.0
.. _adiabaticexpansion_param:
Adiabatic Expansion (22)
~~~~~~~~~~~~~~~~~~~~~~~~
A test for time-integration accuracy of the expansion terms (Bryan
thesis 1996, Sect. 3.3.3).
``AdiabaticExpansionInitialTemperature`` (external)
Initial temperature for Adiabatic Expansion test; test example
assumes 1000 K. Default: 200. Units: degrees Kelvin
``AdiabaticExpansionInitialVelocity`` (external)
Initial expansion velocity. Default: 100. Units: km/s
``AdiabaticExpansionOmegaBaryonNow`` (external)
Omega Baryon at redshift z=0; standard value 1.0. Default: 1.0
``AdiabaticExpansionOmegaCDMNow`` (external)
Omega CDM at redshift z=0; default setting assumes no dark matter.
Default: 0.0
.. _testgravity_param:
Test Gravity (23)
~~~~~~~~~~~~~~~~~
We set up a system in which there is one grid point with mass in
order to see the resulting acceleration field. If finer grids are
specified, the mass is one grid point on the subgrid as well.
Periodic boundary conditions are imposed (gravity).
``TestGravityDensity`` (external)
Density of the central peak. Default: 1.0
``TestGravityMotionParticleVelocity`` (external)
Initial velocity of test particle(s) in x-direction. Default: 1.0
``TestGravityNumberOfParticles`` (external)
The number of test particles of a unit mass. Default: 0
``TestGravitySubgridLeft``, ``TestGravitySubgridRight`` (external)
Start and end positions of the subgrid. Default: 0.0 and 0.0 (no
subgrids)
``TestGravityUseBaryons`` (external)
Boolean switch. Type: integer. Default: 0 (FALSE)
.. _sphericalinfall_param:
Spherical Infall (24)
~~~~~~~~~~~~~~~~~~~~~
A test based on Bertschinger's (1985) 3D self-similar spherical
infall solution onto an initially overdense perturbation in an
Einstein-de Sitter universe.
``SphericalInfallCenter`` (external)
Coordinate(s) for the accretion center. Default: top grid center
``SphericalInfallFixedAcceleration`` (external)
Boolean flag. Type: integer. Default: 0 (FALSE)
``SphericalInfallFixedMass`` (external)
Mass used to calculate the acceleration from spherical infall
(GM/(4*pi*r^3*a)). Default: If SphericalInfallFixedMass is
undefined and ``SphericalInfallFixedAcceleration == TRUE``, then
``SphericalInfallFixedMass = SphericalInfallInitialPerturbation * TopGridVolume``
``SphericalInfallInitialPerturbation`` (external)
The perturbation of initial mass density. Default: 0.1
``SphericalInfallOmegaBaryonNow`` (external)
Omega Baryon at redshift z=0; standard setting. Default: 1.0
``SphericalInfallOmegaCDMNow`` (external)
Omega CDM at redshift z=0. Default: 0.0 (assumes no dark matter)
Default: 0.0
``SphericalInfallSubgridIsStatic`` (external)
Boolean flag. Type: integer. Default: 0 (FALSE)
``SphericalInfallSubgridLeft``, ``SphericalInfallSubgridRight`` (external)
Start and end positions of the subgrid. Default: 0.0 and 0.0 (no
subgrids)
``SphericalInfallUseBaryons`` (external)
Boolean flag. Type: integer. Default: 1 (TRUE)
.. _testgravitysphere_param:
Test Gravity: Sphere (25)
~~~~~~~~~~~~~~~~~~~~~~~~~
Sets up a 3D spherical mass distribution and follows its evolution
to test the gravity solver.
``TestGravitySphereCenter`` (external)
The position of the sphere center. Default: at the center of the
domain
``TestGravitySphereExteriorDensity`` (external)
The mass density outside the sphere. Default: ``tiny_number``
``TestGravitySphereInteriorDensity`` (external)
The mass density at the sphere center. Default: 1.0
``TestGravitySphereRadius`` (external)
Radius of self-gravitating sphere. Default: 0.1
``TestGravitySphereRefineAtStart`` (external)
Boolean flag. Type: integer. Default: 0 (FALSE)
``TestGravitySphereSubgridLeft``, ``TestGravitySphereSubgridRight`` (external)
Start and end positions of the subgrid. Default: 0.0 and 0.0 (no
subgrids)
``TestGravitySphereType`` (external)
Type of mass density distribution within the sphere. Options
include: (0) uniform density distrubution within the sphere radius;
(1) a power law with an index -2.0; (2) a power law with an index
-2.25 (the exact power law form is, e.g., r\ :sup:`-2.25`\ , where
r is measured in units of ``TestGravitySphereRadius``). Default: 0
(uniform density)
``TestGravitySphereUseBaryons`` (external)
Boolean flag. Type: integer . Default: 1 (TRUE)
.. _gravityequilibriumtest_param:
Gravity Equilibrium Test (26)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sets up a hydrostatic exponential atmosphere with the pressure=1.0
and density=1.0 at the bottom. Assumes constant gravitational
acceleration (uniform gravity field).
``GravityEquilibriumTestScaleHeight`` (external)
The scale height for the exponential atmosphere . Default: 0.1
.. _collapsetest_param:
Collapse Test (27)
~~~~~~~~~~~~~~~~~~
A self-gravity test.
``CollapseTestInitialTemperature`` (external)
Initial gas temperature. Default: 1000 K. Units: degrees Kelvin
``CollapseTestNumberOfSpheres`` (external)
Number of spheres to collapse; must be <= ``MAX_SPHERES=10`` (see
``Grid.h`` for definition). Default: 1
``CollapseTestRefineAtStart`` (external)
Boolean flag. Type: integer. If TRUE, then initializing routine
refines the grid to the desired level. Default: 1 (TRUE)
``CollapseTestUseColour`` (external)
Boolean flag. Type: integer. Default: 0 (FALSE)
``CollapseTestUseParticles`` (external)
Boolean flag. Type: integer. Default: 0 (FALSE)
``CollapseTestSphereCoreRadius`` (external)
An array of core radii for collapsing spheres. Default: 0.1 (for
all spheres)
``CollapseTestSphereDensity`` (external)
An array of density values for collapsing spheres. Default: 1.0
(for all spheres)
``CollapseTestSpherePosition`` (external)
A two-dimensional array of coordinates for sphere centers. Type:
float[``MAX_SPHERES``][``MAX_DIMENSION``]. Default for all spheres:
0.5\*(``DomainLeftEdge[dim]`` + ``DomainRightEdge[dim]``)
``CollapseTestSphereRadius`` (external)
An array of radii for collapsing spheres. Default: 1.0 (for all
spheres)
``CollapseTestSphereTemperature`` (external)
An array of temperatures for collapsing spheres. Default: 1.0.
Units: degrees Kelvin
``CollapseTestSphereType`` (external)
An integer array of sphere types. Default: 0
``CollapseTestSphereVelocity`` (external)
A two-dimensional array of sphere velocities. Type:
float[``MAX_SPHERES``][``MAX_DIMENSION``]. Default: 0.0
``CollapseTestUniformVelocity`` (external)
Uniform velocity. Type: float[``MAX_DIMENSION``]. Default: 0 (for all
dimensions)
``CollapseTestSphereMetallicity`` (external)
Metallicity of the sphere in solar metallicity. Default: 0.
``CollapseTestFracKeplerianRot`` (external)
Rotational velocity of the sphere in units of Keplerian velocity,
i.e. 1 is rotationally supported. Default: 0.
``CollapseTestSphereTurbulence`` (external)
Turbulent velocity field sampled from a Maxwellian distribution
with the temperature specified in
``CollapseTestSphereTemperature``
This parameter multiplies the turbulent velocities by its value.
Default: 0.
``CollapseTestSphereDispersion`` (external)
If using particles, this parameter multiplies the velocity
dispersion of the particles by its value. Only valid in sphere type
8 (cosmological collapsing sphere from a uniform density). Default:
0.
``CollapseTestSphereCutOff`` (external)
At what radius to terminate a Bonner-Ebert sphere. Units? Default:
6.5
``CollapseTestSphereAng1`` (external)
Controls the initial offset (at r=0) of the rotational axis. Units
in radians. Default: 0.
``CollapseTestSphereAng2`` (external)
Controls the outer offset (at ``r=SphereRadius`` of the rotational
axis. In both ``CollapseTestSphereAng1`` and
``CollapseTestSphereAng2`` are set, the rotational axis linearly
changes with radius between ``CollapseTestSphereAng1`` and
``CollapseTestSphereAng2``. Units in radians. Default: 0.
``CollapseTestSphereInitialLevel`` (external)
Failed experiment to try to force refinement to a specified level.
Not working. Default: 0.
.. _cosmologysimulation_param:
Cosmology Simulation (30)
~~~~~~~~~~~~~~~~~~~~~~~~~
A sample cosmology simulation.
``CosmologySimulationDensityName`` (external)
This is the name of the file which contains initial data for baryon
density. Type: string. Example: ``GridDensity``. Default: none
``CosmologySimulationTotalEnergyName`` (external)
This is the name of the file which contains initial data for total
energy. Default: none
``CosmologySimulationGasEnergyName`` (external)
This is the name of the file which contains initial data for gas
energy. Default: none
``CosmologySimulationVelocity[123]Name`` (external)
These are the names of the files which contain initial data for gas
velocities. ``Velocity1`` - x-component; ``Velocity2`` - y-component;
``Velocity3`` - z-component. Default: none
``CosmologySimulationParticleMassName`` (external)
This is the name of the file which contains initial data for
particle masses. Default: none
``CosmologySimulationParticlePositionName`` (external)
This is the name of the file which contains initial data for
particle positions. Default: none
``CosmologySimulationParticleVelocityName`` (external)
This is the name of the file which contains initial data for
particle velocities. Default: none
``CosmologySimulationParticleVelocity[123]Name`` (external) This is
the name of the file which contains initial data for particle
velocities but only has one component per file. This is more
useful with very large (>=2048\ :sup:`3`\ ) datasets. Currently
one can only use this in conjunction with
``CosmologySimulationCalculatePositions``. because it expects a
3D grid structure instead of a 1D list of particles. Default:
None.
``CosmologySimulationCalculatePositions`` (external)
If set to 1, Enzo will calculate the particle positions in one of
two ways: 1) By using a linear Zeldo'vich approximation based on
the particle velocities and a displacement factor [dln(growth
factor) / dtau, where tau is the conformal time], which is stored
as an attribute in the initial condition files, or 2) if the user
has also defined either
CosmologySimulationParticleDisplacementName or
CosmologySimulationParticleDisplacement[123]Name, by reading in
particle displacements from an external code and applying those
directly. The latter allows the use of non-linear displacements.
Default: 0.
``CosmologySimulationParticleDisplacementName`` (external)
This is the name of the file which contains initial data for
particle displacements. Default: none
``CosmologySimulationParticleDisplacement[123]Name`` (external) This
is the name of the file which contains initial data for particle
displacements but only has one component per file. This is more
useful with very large (>=2048\ :sup:`3`\ ) datasets. Currently
one can only use this in conjunction with
``CosmologySimulationCalculatePositions``. because it expects a
3D grid structure instead of a 1D list of particles. Default:
None.
``CosmologySimulationNumberOfInitialGrids`` (external)
The number of grids at startup. 1 means top grid only. If >1, then
nested grids are to be defined by the following parameters.
Default: 1
``CosmologySimulationSubgridsAreStatic`` (external)
Boolean flag, defines whether the subgrids introduced at the
startup are static or not. Type: integer. Default: 1 (TRUE)
``CosmologySimulationGridLevel`` (external)
An array of integers setting the level(s) of nested subgrids. Max
dimension ``MAX_INITIAL_GRIDS`` is defined in
``CosmologySimulationInitialize.C`` as 10. Default for all subgrids: 1,
0 - for the top grid (grid #0)
``CosmologySimulationGridDimension[#]`` (external)
An array (arrays) of 3 integers setting the dimensions of nested
grids. Index starts from 1. Max number of subgrids
``MAX_INITIAL_GRIDS`` is defined in ``CosmologySimulationInitialize.C``
as 10. Default: none
``CosmologySimulationGridLeftEdge[#]`` (external)
An array (arrays) of 3 floats setting the left edge(s) of nested
subgrids. Index starts from 1. Max number of subgrids
``MAX_INITIAL_GRIDS`` is defined in ``CosmologySimulationInitialize.C``
as 10. Default: none
``CosmologySimulationGridRightEdge[#]`` (external)
An array (arrays) of 3 floats setting the right edge(s) of nested
subgrids. Index starts from 1. Max number of subgrids
``MAX_INITIAL_GRIDS`` is defined in ``CosmologySimulationInitialize.C``
as 10. Default: none
``CosmologySimulationUseMetallicityField`` (external)
Boolean flag. Type: integer. Default: 0 (FALSE)
``CosmologySimulationInitialFractionH2I`` (external)
The fraction of molecular hydrogen (H_2) at ``InitialRedshift``. This
and the following chemistry parameters are used if ``MultiSpecies`` is
defined as 1 (TRUE). Default: 2.0e-20
``CosmologySimulationInitialFractionH2II`` (external)
The fraction of singly ionized molecular hydrogen (H2+) at
``InitialRedshift``. Default: 3.0e-14
``CosmologySimulationInitialFractionHeII`` (external)
The fraction of singly ionized helium at ``InitialRedshift``. Default:
1.0e-14
``CosmologySimulationInitialFractionHeIII`` (external)
The fraction of doubly ionized helium at ``InitialRedshift``. Default:
1.0e-17
``CosmologySimulationInitialFractionHII`` (external)
The fraction of ionized hydrogen at ``InitialRedshift``. Default:
1.2e-5
``CosmologySimulationInitialFractionHM`` (external)
The fraction of negatively charged hydrogen (H-) at
``InitialRedshift``. Default: 2.0e-9
``CosmologySimulationInitialFractionMetal`` (external)
The fraction of metals at ``InitialRedshift``. Default: 1.0e-10
``CosmologySimulationInitialTemperature`` (external)
A uniform temperature value at ``InitialRedshift`` (needed if the
initial gas energy field is not supplied). Default: 550\*((1.0 +
``InitialRedshift``)/201)\ :sup:`2`\
``CosmologySimulationOmegaBaryonNow`` (external)
This is the contribution of baryonic matter to the energy density
at the current epoch (z=0), relative to the value required to
marginally close the universe. Typical value 0.06. Default: 1.0
``CosmologySimulationOmegaCDMNow`` (external)
This is the contribution of CDM to the energy density at the
current epoch (z=0), relative to the value required to marginally
close the universe. Typical value 0.94. Default: 0.0 (no dark
matter)
``CosmologySimulationManuallySetParticleMassRatio`` (external)
This binary flag (0 - off, 1 - on) allows the user to manually set
the particle mass ratio in a cosmology simulation. Default: 0 (Enzo
automatically sets its own particle mass)
``CosmologySimulationManualParticleMassRatio`` (external)
This manually controls the particle mass in a cosmology simulation,
when ``CosmologySimulationManuallySetParticleMassRatio`` is set to 1.
In a standard Enzo simulation with equal numbers of particles and
cells, the mass of a particle is set to
``CosmologySimulationOmegaCDMNow``/``CosmologySimulationOmegaMatterNow``,
or somewhere around 0.85 in a WMAP-type cosmology. When a different
number of particles and cells are used (128 particles along an edge
and 256 cells along an edge, for example) Enzo attempts to
calculate the appropriate particle mass. This breaks down when
``ParallelRootGridIO`` and/or ``ParallelParticleIO`` are turned on,
however, so the user must set this by hand. If you have the ratio
described above (2 cells per particle along each edge of a 3D
simulation) the appropriate value would be 8.0 (in other words,
this should be set to (number of cells along an edge) / (number of
particles along an edge) cubed. Default: 1.0.
.. _galaxysimulation_param:
Isolated Galaxy Evolution (31)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Initializes an isolated galaxy, as per the Tasker & Bryan series of
papers.
``GalaxySimulationRefineAtStart`` (external)
Controls whether or not the simulation is refined beyond the root
grid at initialization. (0 - off, 1 - on). Default: 1
``GalaxySimulationInitialRefinementLevel`` (external)
Level to which the simulation is refined at initialization,
assuming ``GalaxySimulationRefineAtStart`` is set to 1. Default: 0
``GalaxySimulationSubgridLeft``, ``GalaxySimulationSubgridRight`` (external)
Vectors of floats defining the edges of the volume which is refined
at start. No default value.
``GalaxySimulationUseMetallicityField`` (external)
Turns on (1) or off (0) the metallicity field. Default: 0
``GalaxySimulationInitialTemperature`` (external)
Initial temperature that the gas in the simulation is set to.
Default: 1000.0
``GalaxySimulationUniformVelocity`` (external)
Vector that gives the galaxy a uniform velocity in the ambient
medium. Default: (0.0, 0.0, 0.0)
``GalaxySimulationDiskRadius`` (external)
Radius (in Mpc) of the galax disk. Default: 0.2
``GalaxySimulationGalaxyMass`` (external)
Dark matter mass of the galaxy, in Msun. Needed to initialize the
NFW gravitational potential. Default: 1.0e+12
``GalaxySimulationGasMass`` (external)
Amount of gas in the galaxy, in Msun. Used to initialize the
density field in the galactic disk. Default: 4.0e+10
``GalaxySimulationDiskPosition`` (external)
Vector of floats defining the center of the galaxy, in units of the
box size. Default: (0.5, 0.5, 0.5)
``GalaxySimulationDiskScaleHeightz`` (external)
Disk scale height, in Mpc. Default: 325e-6
``GalaxySimulationDiskScaleHeightR`` (external)
Disk scale radius, in Mpc. Default: 3500e-6
``GalaxySimulationDarkMatterConcentrationParameter`` (external)
NFW dark matter concentration parameter. Default: 12.0
``GalaxySimulationDiskTemperature`` (external)
Temperature of the gas in the galactic disk. Default: 1.0e+4
``GalaxySimulationInflowTime`` (external)
Controls inflow of gas into the box. It is strongly suggested that
you leave this off. Default: -1 (off)
``GalaxySimulationInflowDensity`` (external)
Controls inflow of gas into the box. It is strongly suggested that
you leave this off. Default: 0.0
``GalaxySimulationAngularMomentum`` (external)
Unit vector that defines the angular momentum vector of the galaxy
(in other words, this and the center position define the plane of
the galaxy). This _MUST_ be set! Default: (0.0, 0.0, 0.0)
.. _shearingbox_param:
Shearing Box Simulation (35)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
``ShearingBoxProblemType`` (external)
Value of 0 starts a sphere advection through the shearing box test.
Value of 1 starts a standard Balbus & Hawley shearing box
simulation. Default: 0
``ShearingBoxRefineAtStart`` (external)
Refine the simulation at start. Default: 1.0
``ThermalMagneticRatio`` (external)
Plasma beta (Pressure/Magnetic Field
Energy) Default: 400.0
``FluctuationAmplitudeFraction`` (external)
The magnitude of the sinusoidal velocity perturbations as a
fraction of the angular velocity. Default: 0.1
``ShearingBoxGeometry`` (external)
Defines the radius of the sphere for ``ShearingBoxProblemType`` =
0, and the frequency of the velocity fluctuations (in units of
2pi) for ``ShearingBoxProblemType`` = 1. Default: 2.0
.. _supernovarestart_param:
Supernova Restart Simulation (40)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All of the supernova parameters are to be put into a restart dump
parameter file. Note that ProblemType must be reset to 40,
otherwise these are ignored.
``SupernovaRestartEjectaCenter[#]`` (external)
Input is a trio of coordinates in code units where the supernova's
energy and mass ejecta will be centered. Default: ``FLOAT_UNDEFINED``
``SupernovaRestartEjectaEnergy`` (external)
The amount of energy instantaneously output in the simulated
supernova, in units of 1e51 ergs. Default: 1.0
``SupernovaRestartEjectaMass`` (external)
The mass of ejecta in the supernova, in units of solar masses.
Default: 1.0
``SupernovaRestartEjectaRadius`` (external)
The radius over which the above two parameters are spread. This is
important because if it's too small the timesteps basically go to
zero and the simulation takes forever, but if it's too big then you
loose information. Units are parsecs. Default: 1.0 pc
``SupernovaRestartName`` (external)
This is the name of the restart data dump that the supernova
problem is initializing from.
``SupernovaRestartColourField``
Reserved for future use.
.. _photontest_param:
Photon Test (50)
~~~~~~~~~~~~~~~~
This test problem is modeled after Collapse Test (27), and thus
borrows all of its parameters that control the setup of spheres.
Replace CollapseTest with PhotonTest in the sphere parameters, and
it will be recognized. However there are parameters that control
radiation sources, which makes this problem unique from collapse
test. The radiation sources are fixed in space.
``PhotonTestNumberOfSources`` (external)
Sets the number of radiation sources. Default: 1.
``PhotonTestSourceType`` (external)
Sets the source type. No different types at the moment. Default: 0.
``PhotonTestSourcePosition`` (external)
Sets the source position. Default: 0.5\*(``DomainLeftEdge`` + ``DomainRightEdge``)
``PhotonTestSourceLuminosity`` (external)
Sets the source luminosity in units of photons per seconds.
Default: 0.
``PhotonTestSourceLifeTime`` (external)
Sets the lifetime of the source in units of code time. Default: 0.
``PhotonTestSourceRampTime`` (external)
If non-zero, the source will exponentially increase its luminosity
until it reaches the full luminosity when the age of the source
equals this parameter. Default: 0.
``PhotonTestSourceEnergyBins`` (external)
Sets the number of energy bins in which the photons are emitted
from the source. Default: 4.
``PhotonTestSourceSED`` (external)
An array with the fractional luminosity in each energy bin. The sum
of this array must equal to one. Default: 1 0 0 0
``PhotonTestSourceEnergy`` (external)
An array with the mean energy in each energy bin. Units are in eV.
Default: 14.6 25.6 56.4 12.0 (i.e. HI ionizing, HeI ionizing, HeII
ionizing, Lyman-Werner)
``PhotonTestInitialFractionHII`` (external)
Sets the initial ionized fraction of hydrogen. Default: 1.2e-5
``PhotonTestInitialFractionHeII`` (external)
Sets the initial singly-ionized fraction of helium. Default: 1e-14
``PhotonTestInitialFractionHeIII`` (external)
Sets the initial doubly-ionized fraction of helium. Default: 1e-17
``PhotonTestInitialFractionHM`` (external)
Sets the initial fraction of H\ :sup:`-`\ . Default: 2e-9
``PhotonTestInitialFractionH2I`` (external)
Sets the initial neutral fraction of H2. Default: 2e-20
``PhotonTestInitialFractionH2II`` (external)
Sets the initial ionized fraction of H2. Default: 3e-14
``PhotonTestOmegaBaryonNow`` (obsolete)
Default: 0.05.
.. _coolingtest_param:
Cooling Test (62)
~~~~~~~~~~~~~~~~~
This test problem sets up a 3D grid varying smoothly in log-space in H
number density (x dimension), metallicity (y-dimension), and temperature
(z-dimension). The hydro solver is turned off. By varying the
``RadiativeCooling`` and ``CoolingTestResetEnergies`` parameters, two different
cooling tests can be run. 1) Keep temperature constant, but iterate
chemistry to allow species to converge. This will allow you to make plots
of Cooling rate vs. T. For this, set ``RadiativeCooling`` to 0 and
``CoolingTestResetEnergies`` to 1. 2) Allow gas to cool, allowing one to plot
Temperature vs. time. For this, set ``RadiativeCooling`` to 1 and
``CoolingTestResetEnergies`` to 0.
``CoolingTestMinimumHNumberDensity`` (external)
The minimum density in code units at x=0. Default: 1
[cm\ :sup:`-3`\ ].
``CoolingTestMaximumHNumberDensity`` (external)
The maximum density in code units at
x=``DomainRightEdge[0]``. Default: 1e6
[cm\ :sup:`-3`\ ].
``CoolingTestMinimumMetallicity`` (external)
The minimum metallicity at y=0. Default: 1e-6 [Z\ :sub:`sun`\ ].
``CoolingTestMaximumMetallicity`` (external)
The maximum metallicity at
y=``DomainRightEdge[1]``. Default: 1
[Z\ :sub:`sun`\ ].
``CoolingTestMinimumTemperature`` (external)
The minimum temperature in Kelvin at z=0. Default: 10.0 [K].
``CoolingTestMaximumTemperature`` (external)
The maximum temperature in Kelvin at
z=``DomainRightEdge[2]``. Default: 1e7 [K].
``CoolingTestResetEnergies`` (external)
An integer flag (0 or 1) to determine whether the grid energies
should be continually reset after every iteration of the chemistry
solver such that the temperature remains constant as the mean
molecular weight varies slightly. Default: 1.
Other External Parameters
-------------------------
``huge_number`` (external)
The largest reasonable number. Rarely used. Default: 1e+20
``tiny_number`` (external)
A number which is smaller than all physically reasonable numbers.
Used to prevent divergences and divide-by-zero in C++ functions.
Modify with caution! Default: 1e-20.
An independent analog, ``tiny``, defined in ``fortran.def``, does the same
job for a large family of FORTRAN routines. Modification of ``tiny`` must
be done with caution and currently requires recompiling the code, since
``tiny`` is not a runtime parameter.
``TimeActionParameter[#]``
Reserved for future use.
``TimeActionRedshift[#]``
Reserved for future use.
``TimeActionTime[#]``
Reserved for future use.
``TimeActionType[#]``
Reserved for future use.
Other Internal Parameters
-------------------------
``TimeLastRestartDump``
Reserved for future use.
``TimeLastDataDump`` (internal)
The code time at which the last time-based output occurred.
``TimeLastHistoryDump``
Reserved for future use.
``TimeLastMovieDump`` (internal)
The code time at which the last movie dump occurred.
``CycleLastRestartDump``
Reserved for future use.
``CycleLastDataDump`` (internal)
The last cycle on which a cycle dump was made
``CycleLastHistoryDump``
Reserved for future use.
``InitialCPUTime``
Reserved for future use.
``InitialCycleNumber`` (internal)
The current cycle
``RestartDumpNumber``
Reserved for future use.
``DataLabel[#]`` (internal)
These are printed out into the restart dump parameter file. One
Label is produced per baryon field with the name of that baryon
field. The same labels are used to name data sets in HDF files.
``DataUnits[#]``
Reserved for future use.
``DataDumpNumber`` (internal)
The identification number of the next output file (the 0000 part of
the output name). This is used and incremented by both the cycle
based and time based outputs. Default: 0
``HistoryDumpNumber``
Reserved for future use.
``MovieDumpNumber`` (internal)
The identification number of the next movie output file. Default: 0
``VersionNumber`` (internal)
Sets the version number of the code which is written out to restart
dumps.