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Kevin Volk incorporated three large grids of stellar atmosphere continua into Cloudy, and more have since been added since. The table star atlas, table star Rauch,  table star Werner and table star costar commands use these.  Some of the stellar atmosphere files are very large, and reading them using sequential access would be very slow. Direct access is used to read these files in a timely manner.

It is necessary to have Cloudy compile the stellar atmosphere files before they can be used. This both rebins the atmospheres onto the current Cloudy energy grid, and converts it to a direct access binary format.  This only needs to be done once when the code is first installed, or if the continuum energy mesh is changed. Follow these steps to compile the star files:

There are two steps involved in preparing the star files for use by Cloudy.  The first is to remap the original stellar atmospheres onto the Cloudy energy grid with the compile stars command, as described on this page.  Then use these files with the table star commands as described in Part 1 of Hazy. The first step is only done once while installing Cloudy.  It is not necessary to set up the star files if you do not need these stellar continua.

Download the Atlas and Werner stars

These are available here.  The single file stars.tar.gz will explode into four files, kurucz.list, kurucz.ascii, werner.ascii,  and stars.htm.  Only the first three are needed.

Prepare the Rauch stellar atmospheres

C96 beta 5 and later can use either the "first generation" (H-Ca) models, or the "second generation" (H-Ni) models.  These are referred to as the old and default stellar atmospheres.  C96 beta 4 and before can only use the first generation files.  The compile stars Rauch and table stars Rauch commands will work with the second generation atmospheres by default.  If the keyword "old" appears on the command line the first generation atmospheres will be used instead.  The names of the first and second generation stellar atmosphere files are totally distinct so both sets can happily coexist in the same directory.

The second generation Rauch atmospheres

These instructions are for the "new" Rauch atmospheres, which include effects of the elements between H and Ni.  The new set has two abundance sets, solar and halo. This can only be used with C96 beta 5 and later.  The reference for these emergent continua is

Rauch T., 2002, H-Ni grid, available at http://astro.uni-tuebingen.de/~rauch  The paper describing the stars is available here.

First obtain the tar files from Thomas Rauch’s Web site.  The link http://astro.uni-tuebingen.de/~rauch/flux.html points to the top level for all the stellar atmospheres.  You want the "second generation H-Ni" set. Click on the "H-Ni" link.  At the bottom of the page you will find two sets of atmospheres.  You want the solar and halo abundances dated July 2002 and June 2002 respectively.  The general format for each atmosphere is temperature_gravity_abundances.bin_0.1.

Uncompress and explode both tar files into a directory. This will create a large number of stellar atmosphere files with names ending with the extension "bin_0.1". Next change to the directory with these files and execute Cloudy with the single command

compile stars Rauch initialize

This will read in the large number of smaller files and create the two larger files, rauch02_halo.ascii and rauch02_solar.ascii that are needed for the next step. Only these two files need be retained.

The first generation Rauch atmospheres

These instructions are for initializing the "old" Rauch atmospheres, which include effects of the elements between H and Ca.  The old set has two abundance sets, solar and halo. This set of atmospheres extends to higher temperatures than the second generation set.  Versions of Cloudy before beta 5 of C96 can only use this set.

First obtain the tar files from Thomas Rauch’s Web site.  The link http://astro.uni-tuebingen.de/~rauch/flux.html points to the top level for all the stellar atmospheres.  You want the "first generation H-Ca" set. Click on the "H-Ca" link.  At the bottom of the page you will find several sets of atmospheres.  You want two sets of files, for solar and halo abundances.  These are dated Feb 1998 and May 1998 respectively, and note that they are for versions 90.05 and later.  The general format for each atmosphere is temperature_gravity_abundances.wf.

Uncompress and explode these files in a directory. This will create a large number of stellar atmosphere files with names ending with the extension wf. Next change to the directory with the star files and execute Cloudy with the single command

compile stars old Rauch initialize

This will read in the large number of small files and create the two larger files rauch_halo.ascii and rauch_solar.ascii that are needed for the next step. Only these two files need be retained.

The CoStar spectra

These are developed by Daniel Schaerer and are described in Schaerer D., et al, 1996ab, A&A 310, 837 and A&A 312, 475, and Schaerer & de Koter (1997; A&A 322, 598).  They are available on the web from  http://www.stsci.edu/ftp/science/starburst/SdK96.html . Download both the Sc1_costar_z004_lb.fluxes and Sc1_costar_z020_lb.fluxes files. 

Compiling the star files

At this stage we should have the following sets of files:

werner.ascii This is a plain ASCII version of the Werner and Heber (1991) grid of hot stellar atmospheres and was downloaded from the Cloudy web site. These data extend from 10-5 Ryd through 182.25 Ryd.

kurucz.list This is a list of all files in the Kurucz (1991) grid and was obtained from the Cloudy web site.

kurucz.ascii This is the set of Kurucz (1991) atmospheres obtained from the Cloudy web site. The wavelengths of the grid are stored in nanometers as the first record. These data extend from 9.090 nm (10.0 Ryd) through 1.600´ 105 nm (5.7´ 10-4 Ryd).

rauch_halo.ascii and rauch_solar.ascii These are the sets of first generation Rauch hot stellar atmospheres,  as produced above with the compile stars old rauch initialize command.  (you don't need this set if you only want to use the second generation atmospheres).

rauch02_halo.ascii and rauch02_solar.ascii These are the sets of second generation Rauch hot stellar atmospheres,  as produced above with the compile stars rauch initialize command.

Sc1_costar_z004_lb.fluxes and Sc1_costar_z020_lb.fluxes - The set of CoStar stellar atmospheres from the STScI site described above.

Compiling all the star files

Move into the directory where the files kurucz.ascii, kurucz.list, rauch_halo.ascii, rauch_solar.ascii, rauch02_halo.ascii, rauch02_solar.ascii, Sc1_costar_z004_lb.fluxes, Sc1_costar_z020_lb.fluxes and werner.ascii  live.

If you want all the stellar continua just execute Cloudy with the single command compile stars as input. The file compilestars.in that is included in the data distribution will do this - you would only need to execute this script.  Examine the resulting output for any comments indicating success or failure. I do this with the output coming to the screen so that I can monitor progress. This step typically takes about 15 minutes on my PC. 

The previous command only compiles the second generation Rauch stars.  If you also want to use the first generation atmospheres then it is also necessary to run the program a second time, with the single command compile stars only old Rauch

It is possible that only some of these stellar continua are needed.  In this case use the "compile stars only xxx" command to compile the continua you need.  The xxx options are "atlas", costar, Rauch, and Werner and this is described further below.

The direct access files atlas.mod, rauch_halo.mod, rauch_solar.mod, rauch02_halo.mod, rauch02_solar.mod, costar_halo.mod, costar_sol.mod, and werner.mod will be created by the compile step. These are the files which Cloudy must access to use the table star atlas, table star Rauch, table star costar, or table star Werner continua. Only these files need be kept, and they should be placed in the data directory, as described next. 

To execute the code from other directories it is necessary to have the path set to point to the directory containing the star files.  This can be done with the set path command described in part I of Hazy, but it is far more convenient to put the *.mod files in the same directory where the atomic data live.  If you edited the file path.c to point to the data directory then the code will automatically be able to find the stellar continua data.  

When doing later photoionization calculations, the code will stop before computing a model if it cannot locate the files when the corresponding table stars command is entered. The code also checks that the energy grids in the star files and the code itself agree, to confirm that the star files are appropriate for the current version of Cloudy.

Cleaning up after compilation

Only the *.mod files are needed by Cloudy. The other files can be deleted or compressed after the compilation is complete. They will only be needed again if the continuum binning within the code is changed. The Rauch star files will never be needed again, unless one of the atmospheres is updated and it is necessary to recreate the set.

Compiling only one of the star sets

Often only one or two of the sets of stellar atmospheres are needed, not the whole lot.   The only option on the compile stars command was introduced to make this possible.  Follow the instructions above, although you only need to get the files needed for the desired atmospheres.  Then execute the compile command with the only keyword, and another keyword identifying the stellar atmosphere, as follows:

compile only atlas stars
compile only werner stars
compile only rauch stars
compile only old rauch stars
compile only costar stars

The code will only try to read the indicated atmosphere, and produce only that mod file.

If the continuum binning is changed

The resolution of the continuum mesh can be changed by changing the contents of the file continuum_mesh.dat in the data directory.  The code checks that the energy mesh within the compiled stellar atmosphere file agrees exactly with the code's internal grid, and will stop if they do not agree to within the machine precision.  If the continuum binning by changing continuum_mesh.dat then it will be necessary to recompile the star files, using the compile stars command.

Next step: run the test suite.

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