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bapec, bvapec: velocity broadened APEC thermal plasma model

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

,where DA is the angular diameter distance to the source (cm), ne and nH are the electron and H densities (cm-3)

 

 

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

,where DA is the angular diameter distance to the source (cm), ne and nH are the electron and H densities (cm-3)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

next up previous contents
Next: Bbody Up: Additive Model Components Previous: Atable