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brnei, bvrnei, bvvrnei: velocity-broadened non-equilibrium recombining collisional plasma

Velocity-broadened non-equilibrium ionization collisional plasma model. This is a beta test version of a model for a recombining plasma where the plasma is assumed to have started in collisional equilibrium with the initial temperature given by the relevant input parameter. This model will only work for xset neivers 3.0 and above. All lines in this model are thermally broadened as well as velocity broadened by the amount specified by the input parameter.

The bvrnei variant allows the user to set the abundances of the most common elements. The abundances of the trace elements (ie Li, Be, B, F, Na, P, Cl, K, Sc, Ti, V, Cr, Mn, Co, Cu, Zn) can be set using xset NEI_TRACE_ABUND. These trace element abundances can be set either to the abundance of one of the main elements or to a numerical value (relative to Solar). For instance,

XSPEC12> xset NEI_TRACE_ABUND Fe
sets trace element abundances to that of iron while
XSPEC12> xset NEI_TRACE_ABUND 1.0
sets them to Solar. The default value for NEI_TRACE_ABUND is 1.0. Full control over all the elemental abundances is available in the bvvrnei model.

The continuum and line emission files used can be changed using the xset neiapecroot command. There are several options. NEIAPECROOT can be set to a version number (eg 3.0.7). In this case the value of NEIAPECROOT will be used to replace the default version number 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_v3.0.7) can be given. This root will be used as a prefix for the _nei_comp.fits and _nei_line.fits files. Finally, if neither of these work then the model will assume that the NEIAPECROOT value gives the complete directory path, e.g.

XSPEC12> xset NEIAPECROOT /foo/bar/apec_v3.0.7

For the brnei model the parameters are:

par1 Plasma temperature (keV)
par2 Initial plasma temperature (keV)
par3 Metal abundances (He fixed at cosmic). The elements included are C, N, O, Ne, Mg, Si, S, Ar, Ca, Fe, Ni. Abundances are defined by the abund command
par4 Ionization timescale in units of s/cm$^3$.
par5 redshift
par6 Velocity broadening (km/s)
norm $(10^{-14}/(4\pi[D_A(1+z)]^2))\int n_en_H dV$, where $D_A$ is the angular diameter distance to the source (cm), $n_e$ is the electron density (cm$^{-3}$), and $n_H$ is the hydrogen density (cm$^{-3}$).

For the bvrnei model, the parameters are:

par1 Plasma temperature (keV)
par2 Initial plasma temperature (keV)
par3 H abundance (should take values of 0 or 1 to switch on and off free-free continuum)
par4-par15 Abundances for He, C, N, O, Ne, Mg, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command)
par16 Ionization timescale in units of s/cm$^3$.
par17 Redshift, z
par18 Velocity broadening (km/s)
norm $(10^{-14}/(4\pi[D_A(1+z)]^2))\int n_en_H dV$, where $D_A$ is the angular diameter distance to the source (cm), $n_e$ is the electron density (cm$^{-3}$), and $n_H$ is the hydrogen density (cm$^{-3}$).

Finally, for the bvvrnei model, the parameters are:

par1 Plasma temperature (keV)
par2 Initial plasma temperature (keV)
par3 H abundance (should take values of 0 or 1 to switch on and off free-free continuum)
par4-par32 Abundances for all elements with 2 $\leq$ Z $\leq$ 30 wrt Solar (defined by the abund command)
par33 Ionization timescale in units of s/cm$^3$.
par34 Redshift, z
par35 Velocity broadening (km/s)
norm $(10^{-14}/(4\pi[D_A(1+z)]^2))\int n_en_H dV$, where $D_A$ is the angular diameter distance to the source (cm), $n_e$ is the electron density (cm$^{-3}$), and $n_H$ is the hydrogen density (cm$^{-3}$).


next up previous contents
Next: btapec, bvtapec, bvvtapec: velocity Up: Additive Model Components Previous: bremss, vbremss, zbremss: thermal