A velocity- and thermally-broadened emission spectrum from collisionally-ionized diffuse gas calculated using the APEC code v1.3.1. More information on APEC can be found at
http://hea-www.harvard.edu/APEC
which should be consulted by anyone running this model. By default this model reads atomic physics continuum and line data from apec_v[version]_coco.fits and apec_v[version]_line.fits in the $HEADAS/../spectral/modelData directory. Different files can be specified by using the command xset APECROOT. There are three options. APECROOT can be set to a version number (eg 1.10, 1.2.0, 1.3.1). In this case the value of APECROOT will be used to replace 1.3.1 in the name of the standard files and the resulting files will be assumed to be in the modelData directory. Alternatively, a filename root (eg apec_v1.2.0) can be given. This root will be used as a prefix for the _coco.fits and _line.fits files. Finally, if neither of these work then the model will assume that the APECROOT value gives the complete directory path, e.g.
XSPEC12> xset APECROOT /foo/bar/apec_v1.2.0
will use the input files
/foo/bar/apec_v1.2.0_coco.fits
/foo/bar/apec_v1.2.0_line.fits.
The bapec model uses abundances set by the abund command. The bvapec variant allows the user to set the abundance using additional parameters.
par1 |
plasma temperature, keV |
par2 |
Metal abundances (He fixed at cosmic). The elements included are C, N, O, Ne, Mg, Al, Si, S, Ar, Ca, Fe, Ni. Relative abundances are set by the abund command. |
par3 |
Redshift, z |
par4 |
Gaussian sigma for velocity broadening (km/s) |
norm |
|
For the bvapec variant the parameters are as follows.
par1 |
plasma temperature, keV |
par2-par14 |
Abundances for He, C, N, O, Ne, Mg,Al, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command) |
par15 |
redshift, z |
par16 |
Gaussian sigma for velocity broadening (km/s) |
norm |
|