set_xsabund

Context: modeling

Synopsis

Set the elemental abundances used by X-Spec models.

set_xsabund(abundance)

Set the abundance table used in the X-Spec plasma emission and photoelectric absorption models. It is equivalent to the X-Spec abund command [1] .

>>> set_xsabund('lodd')
 Solar Abundance Vector set to lodd:  Lodders, K. ApJ 591, 1220 (2003)

>>> set_xsabund('abund.dat')
 Solar Abundance Vector set to file:  User defined abundance vector / no description specified

The parameter for this function is:

Parameter	Type information	Definition
abundance	str	A file name, format described below, or one of the pre-defined names listed in the Notes section below.

The pre-defined abundance tables are:

'angr', from [2]
'aspl', from [3]
'feld', from [4] , except for elements not listed which are given 'grsa' abundances
'aneb', from [5]
'grsa', from [6]
'wilm', from [7] , except for elements not listed which are given zero abundance
'lodd', from [8]
'lpgp', from [9] (photospheric)
'lpgs', from [9] (proto-solar)

The values for these tables are given at [1] .

Data files should be in ASCII format, containing a single numeric (floating-point) column of the abundance values, relative to Hydrogen.

The screen output of this function is controlled by the X-Spec chatter setting ( `set_xschatter` ).

[1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSabund.html Note that this may refer to a newer version than the compiled version used by Sherpa; use `get_xsversion` to check.
[2] Anders E. & Grevesse N. (1989, Geochimica et Cosmochimica Acta 53, 197) https://adsabs.harvard.edu/abs/1989GeCoA..53..197A
[3] Asplund M., Grevesse N., Sauval A.J. & Scott P. (2009, ARAA, 47, 481) https://adsabs.harvard.edu/abs/2009ARA%26A..47..481A
[4] Feldman U.(1992, Physica Scripta 46, 202) https://adsabs.harvard.edu/abs/1992PhyS...46..202F
[5] Anders E. & Ebihara (1982, Geochimica et Cosmochimica Acta 46, 2363) https://adsabs.harvard.edu/abs/1982GeCoA..46.2363A
[6] Grevesse, N. & Sauval, A.J. (1998, Space Science Reviews 85, 161) https://adsabs.harvard.edu/abs/1998SSRv...85..161G
[7] Wilms, Allen & McCray (2000, ApJ 542, 914) https://adsabs.harvard.edu/abs/2000ApJ...542..914W
[8] Lodders, K (2003, ApJ 591, 1220) https://adsabs.harvard.edu/abs/2003ApJ...591.1220L
[9] Lodders K., Palme H., Gail H.P., Landolt-Börnstein, New Series, vol VI/4B, pp 560–630 (2009) https://ui.adsabs.harvard.edu/abs/2009LanB...4B..712L/abstract

CIAO 4.17 comes with support for version 12.14.0k of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.14.0k

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.