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 that defined by the abund
command). 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. |
par5 |
redshift |
par6 |
Velocity broadening (km/s) |
norm |
, where is the angular diameter distance to the source
(cm), is the volume element (cm), and and are the
electron and H densities (cm), respectively |
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. |
par17 |
Redshift, z |
par18 |
Velocity broadening (km/s) |
norm |
, where is the angular diameter distance to the source
(cm), is the volume element (cm), and and are the
electron and H densities (cm), respectively |
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 Z 30 wrt Solar (defined by the abund command) |
par33 |
Ionization timescale in units of s/cm. |
par34 |
Redshift, z |
par35 |
Velocity broadening (km/s) |
norm |
, where is the angular diameter distance to the source
(cm), is the volume element (cm), and and are the
electron and H densities (cm), respectively |
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Last modified: Tuesday, 28-May-2024 10:09:22 EDT
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