sedov, vsedov: sedov model, separate ion/electron temperature
Sedov model with separate ion and electron temperatures. This model is slow. par1 provides a measure of the average energy per particle (ions+electrons) and is constant throughout the postshock flow in plane shock models (Borkowski et al., 2001, ApJ, 548, 820). par2 should always be less than par1. If par2 exceeds par1 then their interpretations are switched (ie the larger of par1 and par2 is always the mean temperature). Additional references can be found under the help for the equil model. Several versions are available. To switch between them use the xset neivers command. xset neivers 1.0 gives the version from xspec v11.1, xset neivers 1.1 uses updated calculations of ionization fractions using dielectronic recombination rates from Mazzotta et al (1988), and xset neivers 2.0 uses the same ionization fractions as 1.1 but uses APED to calculate the resulting spectrum. Note that versions 1.x have no emission from Ar. The default is version 1.1.
The sedov model has relative abundances determined by the solar Anders and Grevesse mixture, while the vsedov variant allows the user to set the abundances.
Parameters for sedov are:
par1 |
mean shock temperature (keV) |
par2 |
electron temperature immediately behind the shock front (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 given by the Anders & Grevesse mixture. |
par4 |
ionization age (s cm–3) of the remnant (= electron density immediately behind the shock front multiplied by the age of the remnant) |
par5 |
redshift z |
norm |
where DA is the angular size distance to the source (cm) , and ne , nH (cm-3) are the electron and hydrogen densities respectively. |
For vsedov the parameters are:
par1 |
mean shock temperature (keV) |
par2 |
electron temperature immediately behind the shock front (keV) |
par3 |
H density in cm-3 |
par4-par15 |
Abundances for He, C, N, O, Ne, Mg, Si, S, Ar, Ca, Fe, Ni wrt Solar (given by the Anders & Grevesse mixture) |
par4 |
ionization age (s cm–3) of the remnant (= electron density immediately behind the shock front multiplied by the age of the remnant) |
par5 |
redshift z |
norm |
where DA is the angular size distance to the source (cm) , and ne , nH (cm-3) are the electron and hydrogen densities respectively. |