cempow, vcempow, bcempow, bvcempow: plasma emission, multi-temperature using a power-law emission measure

A multi-temperature plasma emission model. Emission measures follow a power-law in temperature ( $dEM = (T/T_{max})^{\alpha-1}dT/T_{max}$).The switch parameter determines whether the spectrum is calculated by running the mekal code, by interpolating on a pre-calculated mekal table, using the AtomDB data, or the SPEX data. The final two options are now preferred. See the cie model for further information and options.

For the cempow and bcempow versions, the abundance ratios are set by the abund command. The vcempow and bvcempow variants allow the user to define the abundances. The reference for this model is Singh et al. (1996, ApJ, 456, 766).

Velocity broadening can only be used with switch=2 or switch=3.

For cempow the parameters are:

par1	$\alpha$, index for power-law emissivity function
par2	$T_{max}$, maximum temperature
par3	$n_H$ (cm$^{-3}$
par4	Abundance relative to Solar
par5	z, redshift
par6	Switch (0 = calculate using mekal, 1 = interpolate using mekal, 2 = use AtomDB data, 3 = use SPEX data).
norm	Normalization

For the vcempow variant the parameters are:

par1	$\alpha$, index for power-law emissivity function
par2	$T_{max}$, maximum temperature
par3	$n_H$ (cm$^{-3}$
par4–17	Abundances of He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command)
par18	z, redshift
par19	Switch (0 = calculate using mekal, 1 = interpolate using mekal, 2 = use AtomDB data, 3 = use SPEX data).
norm	Normalization

For bcempow the parameters are:

par1	$\alpha$, index for power-law emissivity function
par2	$T_{max}$, maximum temperature
par3	$n_H$ (cm$^{-3}$
par4	Abundance relative to Solar
par5	z, redshift
par6	Gaussian sigma for velocity broadening (km/s) (switch=2 only)
par7	Switch (0 = calculate using mekal, 1 = interpolate using mekal, 2 = use AtomDB data, 3 = use SPEX data).
norm	Normalization

For the bvcempow variant the parameters are:

par1	$\alpha$, index for power-law emissivity function
par2	$T_{max}$, maximum temperature
par3	$n_H$ (cm$^{-3}$
par4–17	Abundances of He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command)
par18	z, redshift
par19	Gaussian sigma for velocity broadening (km/s) (switch=2 only)
par20	Switch (0 = calculate using mekal, 1 = interpolate using mekal, 2 = use AtomDB data, 3 = use SPEX data).
norm	Normalization

HEASARC Home | Observatories | Archive | Calibration | Software | Tools | Students/Teachers/Public

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.