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tapec, vtapec, vvtapec: APEC emission spectrum with separate continuum and line temperatures

An emission spectrum from collisionally-ionized diffuse gas calculated from the AtomDB atomic database. More information can be found at http://atomdb.org/ which should be consulted by anyone running this model. This version of the model allows different temperatures for the continuum and lines. This default version number can be changed by modifying the ATOMDB_VERSION string in your Xspec.init file.

See the documentation on the apec model for a list of the xset options which can be used to change the behaviour of the apec code.

For the tapec model the parameters are:

par1=$kT$ continuum temperature, keV
par2=$kTi$ line temperature, keV
par3 Metal abundances (He fixed at that defined by the abund command). The elements included are C, N, O, Ne, Mg, Al, Si, S, Ar, Ca, Fe, Ni. Relative abundances are set by the abund command. The trace element abundances are from xset APEC_TRACE_ABUND, the default is 1.0.
par4 Redshift, z
norm ${10^{-14}\over{4\pi[D_A(1+z)]^2}}\int n_en_HdV$, where $D_A$ is the angular diameter distance to the source (cm), $dV$ is the volume element (cm$^3$), and $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively

For the vtapec variant the parameters are as follows.

par1=$kT$ continuum temperature, keV
par2=$kTi$ line temperature, keV
par3–par15 Abundances for He, C, N, O, Ne, Mg,Al, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command). The trace element abundances are from xset APEC_TRACE_ABUND, the default is 1.0.
par16 redshift, z
norm ${10^{-14}\over{4\pi[D_A(1+z)]^2}}\int n_en_HdV$, where $D_A$ is the angular diameter distance to the source (cm), $dV$ is the volume element (cm$^3$), and $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively

For the vvtapec variant the parameters are as follows.

par1=$kT$ continuum temperature, keV
par2=$kTi$ line temperature, keV
par3–par32 Abundances for H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn wrt Solar (defined by the abund command)
Par33 redshift, z
norm ${10^{-14}\over{4\pi[D_A(1+z)]^2}}\int n_en_HdV$, where $D_A$ is the angular diameter distance to the source (cm), $dV$ is the volume element (cm$^3$), and $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively
next up previous contents Xspec Home Page
Next: wdem, vwdem, vvwdem, bwdem, Up: Additive Model Components Previous: step: step function convolved
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Last modified: Friday, 23-Aug-2024 13:20:40 EDT

HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.