next up previous contents
Next: mkcflow, vmcflow: cooling flow, Up: Additive Model Components Previous: meka, vmeka: emission, hot


mekal, vmekal: emission, hot diffuse gas (Mewe-Gronenschild-Kaastra)

An emission spectrum from hot diffuse gas based on the model calculations of Mewe and Kaastra with Fe L calculations by Liedahl. The model includes line emissions from several elements. The switch parameter determines whether spectrum is calculated by running the mekal code, by interpolating on a pre-calculated mekal table, or using the AtomDB data. Relative abundances are set by the abund command for the mekal model. The vmekal variant allows the user to set the individual abundances for the model.

For the mekal model the parameters are:

par1 plasma temperature in keV
par2 H density (cm$^{-3}$
par3 Metal abundances (He fixed at cosmic). The elements included are C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni. Relative abundances are set by the abund command.
par4 Redshift, z
par5 Switch (0 = calculate, 1 = interpolate, 2 = interpolate using AtomDB data)
norm ${10^{-14}\over{4\pi[D_A(1+z)]^2}}\int n_en_HdV$, where $D_A$ is the angular diameter distance to the source (cm), $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively

For the vmekal variant the parameters are as follows.

par1 plasma temperature in keV
par2 H density (cm$^{-3}$
par3-par16 Abundances for He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni wrt Solar (defined by the abund command).
par17 redshift, z
par18 Switch (0 = calculate, 1 = interpolate, 2 = interpolate using AtomDB data)
norm ${10^{-14}\over{4\pi[D_A(1+z)]^2}}\int n_en_HdV$, where $D_A$ is the angular diameter distance to the source (cm), $n_e$ and $n_H$ are the electron and H densities (cm$^{-3}$), respectively

The references for the meka model are as follows :
Mewe, R., Gronenschild, E.H.B.M., and van den Oord, G.H.J. 1985 A&AS, 62, 197
Mewe, R., Lemen, J.R., and van den Oord, G.H.J. 1986, A&AS, 65, 511
Kaastra, J.S. 1992, An X-Ray Spectral Code for Optically Thin Plasmas (Internal SRON-Leiden Report, updated version 2.0)
Liedahl, D.A., Osterheld, A.L., and Goldstein, W.H. 1995, ApJL, 438, 115

Similar credit may also be given for the adopted ionization balance:
Arnaud, M., and Rothenflug, M. 1985, A& AS, 60, 425
Arnaud, M., and Raymond, J. 1992, ApJ, 398, 394


next up previous contents
Next: mkcflow, vmcflow: cooling flow, Up: Additive Model Components Previous: meka, vmeka: emission, hot