Overview of the stellar continua
Introduction
This page describes how to set up the stellar continua in versions C07 and later of Cloudy. The ability to read in tables of stellar atmospheres was originally introduced into Cloudy by Kevin Volk around 1990. The current versions use Peter van Hoof's unified treatment with a single code base and many more stellar continua. This page describes the stellar atmospheres used in Cloudy versions C06.02 and before.
Peter van Hoof wrote this part of Cloudy and is the maintainer. Please post questions, comments, and suggestions for new stellar atmosphere grids on the Cloudy discussion board.
The section outlines the general method for setting up individual stellar atmosphere grids. Many of the grids are very large and accessing them as ascii files would be slow. They are "compiled" to create direct access binary files. These files, with names ending in "mod", are the files that Cloudy actually uses.
The following sections describes how to download the original ascii stellar continua files. These files can be placed in any temporary directory. The mod files that are created must be accessible to the code for the table stars commands to work. The mod files should be moved to the data directory that was created when the code was set up.
Each grid of stellar continua, along with a link to the paper or web site describing it, is given below. If you use one of these grids in a publication it is very important that you properly cite the original paper describing that grid! It is intellectually lazy, and deprives the original authors of their proper citation, to simply state that you used a continuum that was available in Cloudy.
Procedure for setting up a stellar continuum grid
This describes the general procedure for setting up an individual stellar continuum grid. The method is basically the same for all the grids.
1) Download the files giving the grid from the individual web sites listed below. Some are the original author's web site while other files are located in the "stars" directory below the main Cloudy ftp site. Most have names that end in ascii. An example is ostar2002_p03.ascii (a file from the Tlusty web site). You only need to download the files that you will use. All of the files are needed for the table stars commands to be fully functional.
2) Place all the downloaded files in the same directory. The files have been compressed with gzip. Explode the files using the command "tar -xf *.gz"
3) Cloudy should already have been set up if you got to this page by following the usual steps. I assume you used the recommended directory structure and that the atomic data files are located in a directory data and that Cloudy can be run from any directory. The downloaded grid files are now are located in their own temporary directory.
4) Execute Cloudy with the single command compile stars in the directory containing the downloaded stellar continua. I would do this by first creating a file compile.in containing only this command and then running the code as run compile, which directs its output to compile.out.
5) One mod file will be created for each of the downloaded stellar continuum files. An example is ostar2002_p03.mod which is created from the file ostar2002_p03.ascii. Move the *.mod files into the data directory. You do not need to keep the original ascii files.
If you don't set up all the stellar continua
The Cloudy download includes a large body of test cases that are designed to confirm that the code gets the right answer. Running the test suite is an important part of setting up the code and is described here.
The test suite includes a number of test cases that are designed to check that the stellar continua can be correctly accessed with the table stars command. These tests are in the tsuite/auto directory and have names that start with "stars_". The command ls stars*.in will list them all. You would need to download all of the stellar continua for all of the star tests to work.
If you decide not to download all of the stellar continua then the stars_* test that uses the missing continuum will fail. This is not a problem but is a reminder that some of the table stars commands will not work.
How to find out which grids and parameters you have installed
Two commands will generate lists of the available grids. You can use these to document which grids are installed after the code has been set up.
table star available will list the available grids with parameters. The last few lines of the output it generates on my system appear as follows:
table star tlusty Ostar 3-dim <Teff> <log(g)> <log(Z)>
table star werner <Teff> [ <log(g)> ]
table star wmbasic <Teff> <log(g)> <log(Z)>
This shows that the Tlusty O star grid has three parameters, the temperature, gravity, and metallicity. The Werner star grid has two parameters, and the WMBasic grid has three. This file lists all the grids available with version C07.
table star <grid> list will list the contents of that grid.
Details about individual stellar grids
The following subsections describe details of each of the grids now in the code.
Atlas and Atlas odfnew
These files have names atlas_*_ascii.gz and atlas_*_odfnew.ascii.gz. There were obtained from the Kurucz web site which gives further details about the grids. They were rebinned by PvH and are available in the "stars" directory below the main Cloudy ftp site.
The files atlas_*.ascii.gz are the original Kurucz Atlas continua [xx ref]. The files atlas_*_odfnew.ascii.gz are from xx ref.
Tlusty O and B star grids
The Tlusty code is maintained by Ivan Hubeny & Thierry Lanz. They have produced extensive grids of O and B star continua. The "SEDS for Cloudy" link that is on the left sidebar of their main web site gives links to the files we use.
There are 11 sets of O star continua with names "ostar2002_*.ascii.gz" [described in the reference Lanz, T., & Hubeny, I. 2003, ApJS, 146, 417 (Abstract) (PDF)]. These continua are used by the stars_ostar2002*.in simulations in the test suite.
At the time of this writing the B star grid is still under construction. There are 7 sets of B stars continua with names "bstar2006_*.ascii.gz". These continua are used by the stars_bstar2006*.in simulations in the test suite.
For all parts of the test suite to run cleanly you will need all they files since they are all tested. But a general user will not need all the files, you have a couple of choices instead. If you want everything then either all the 2D files, or the 3D file plus the zero metallicity file, would suffice. If you want to interpolate in log(Z) then you must have the 3D file. But if you are only interested in solar metallicity then the ostar2002_p00.ascii.gz and bstar2006_p00.ascii.gz files are enough.
Kurucz79 O and B stars
This is a subset of the Kurucz (Kurucz, R. L. 1979, ApJS, 40, 1, on the ADS here) grid of stellar continua. They have solar metallicity, log g = 4, and temperatures between 30,000 K and 55,000 K. It is contained in the file kurucz79.ascii.gz in the stars directory below the main Cloudy ftp site. This grid is only included for backwards compatibility. You should use the Atlas grids described above.
Mihalas NLTE hot stars
This is a subset of the Mihalas (Mihalas, D. 1972, Non-LTE Model Atmospheres for B & O Stars, NCAR-TN/STR-76) non-LTE O and B star continua. Most have log g of 4.5. The temperature range is from 30,000 K to 50,000 K. The grid is contained in the file mihalas.ascii.gz in the stars directory below the main Cloudy ftp site. This grid is only included for backwards compatibility.
Rauch PN Nuclei
Thomas Rauch's web site gives sets of continua under "stellar fluxes" in the left sidebar. He gives both first and second generation grids. The site has tarballs with ascii files for each atmosphere (one tarball for each grid). You only need to unpack these tarballs. [xxx is this all?]
Starburst99
The file starburst99.ascii.gz is available in the "stars" directory below the main Cloudy ftp site. The original file was created with the Starburst99 code, as described here. [must be completed xxx]
Werner PN Nuclei
This is the Werner and Heber [Werner, K., & Heber, U. 1991, in Stellar Atmospheres: Beyond Classical Models, p 341, NATO ASI Series C, eds. L. Crivellari, I. Hubney, & D. G. Hummer, (Dordrect: Kluwer)] grid of non-LTE model planetary nebula nuclei atmospheres. It is the file kwerner.ascii.gz in the "stars" directory below the main Cloudy ftp site.
WMBasic O and B stars
The WMBasic code is maintained by Adi Pauldrach who has a home page here. He has computed a grid of hot stars with a range of metallicities. The original grid of models is here and is described in Pauldrach et al., 2001. Peter van Hoof rebinned these files to create the wmbasic.ascii.gz file that is available in the "stars" directory that is below the root directory of the Cloudy ftp site.
Next step: run the test suite.
Last changed 11/04/06.
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Copyright 1978-2006 Gary J. Ferland