c6mekl, c6vmekl, c6pmekl, c6pvmkl: differential emission measure using Chebyshev representations with multi-temperature mekal

c6mekl is a multi-temperature mekal model using sixth-order Chebyshev polynomial for the differential emission measure. The DEM is not constrained to be positive.. The switch parameter determines whether the mekal code will be run to calculate the model spectrum for each temperature or whether  the model spectrum will be interpolated from a pre-calculated table. The former is slower but more accurate. The reference for this model is Singh et al. (1996, ApJ, 456, 766).

c6pmekl differs by using the exponential of the 6^th order Chebyshev polynomial

c6mekl and c6pmekl use abundances relative to the Solar abundances set by the abund command

The variants c6vmkl and c6pvmkl with polynomial and exponential polynomial respectively allow the user to specify 14 elemental abundance.

 

For c6mekl and c6pmkl the parameters are:

par1-6	Chebyshev polynomial coefficients
par7	H density (cm-3)
par8	abundance wrt to Solar
par9	Redshift
par10	0    calculate
	1    interpolate
	2    interpolate using APEC model
norm	where DA is the angular size distance to the source (cm), ne is the electron density (cm-3), and nH is the hydrogen density (cm-3)

While for c6vmkl and c6vpmkl the parameters are:

par1-6	Chebyshev polynomial coefficients
par7	H density (cm-3)
par8-21	Abundances of He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command)
par22	Redshift
par23	0    calculate
	1    interpolate
	2    interpolate using APEC model
norm	where DA is the angular size distance to the source (cm), ne is the electron density (cm-3), and nH is the hydrogen density (cm-3)