A thermal bremsstrahlung spectrum based on the Kellogg, Baldwin & Koch (1975, ApJ 199, 299) polynomial fits to the Karzas & Latter (1961, ApJS 6, 167) numerical values. A routine from Kurucz (private communication) is used at the low temperature end. The He abundance is assumed to be 8.5 % of H by number.
The zbremss variant includes a choice of redshift and vbremss allows the H to He abundance ratio to be varied.
For bremss:
par1 | plasma temperature in keV |
norm | , where is the distance to the source (cm) and , are the electron and ion densities (cm) |
For zbremss:
par1 | plasma temperature in keV |
par2 | z, redshift |
norm | , where is the distance to the source (cm) and , are the electron and ion densities (cm) |
For vbremss:
par1 | plasma temperature in keV |
par2 | ((note that the Solar ratio is 0.085) |
norm | , where is the distance to the source (cm) and , are the electron and ion densities (cm) |