btapec, bvtapec, bvvtapec: velocity broadened APEC emission spectrum with separate continuum and line temperatures

A velocity- and thermally-broadened 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 modifiying 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 btapec model the parameters are:

par1=$kT$	continuum temperature, keV
par2=$kTi$	line temperature, keV
par3	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. The trace element abundances are from xset APEC_TRACE_ABUND, the default is 1.0.
par4	Redshift, z
par5	Gaussian sigma for velocity broadening (km/s)
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), $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively

For the bvtapec 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
par17	Gaussian sigma for velocity broadening (km/s)
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), $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively

For the bvvtapec 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
Par34	Gaussian sigma for velocity broadening (km/s)
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), $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively