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ismabs: A high resolution ISM absorption model with variable columns for individual ions

This is an X-ray photoabsorption model for the interstellar medium that takes into account both neutral and ionized species from H, He, N, O, Ne, Mg, Si, S, Ar, Ca, Fe, Ni and Zn. This model has been developed by Efrain Gatuzz in collaboration with Javier Garcia, Tim Kallman, Claudio Mendoza, and Tom Gorczyca. A complete description of the science behind the model is described in Gatuzz et al. (2015).

Note that the He I column density is not included as a free parameter in the model, due to an inherent degeneracy between the relative columns of H, He I, He II. Instead, the He I column is assumed to be one tenth that of the H column.

The sources of the cross-sections are as follows:

The parameters are:

par1 H column (in units of $10^{22}$ cm$^-2$)
par2 He II column (in units of $10^{16}$ cm$^-2$)
par3 C I column (in units of $10^{16}$ cm$^-2$)
par4 C II column (in units of $10^{16}$ cm$^-2$)
par5 C III column (in units of $10^{16}$ cm$^-2$)
par6 N I column (in units of $10^{16}$ cm$^-2$)
par7 N II column (in units of $10^{16}$ cm$^-2$)
par8 N III column (in units of $10^{16}$ cm$^-2$)
par9 O I column (in units of $10^{16}$ cm$^-2$)
par10 O II column (in units of $10^{16}$ cm$^-2$)
par11 O III column (in units of $10^{16}$ cm$^-2$)
par12 Ne I column (in units of $10^{16}$ cm$^-2$)
par13 Ne II column (in units of $10^{16}$ cm$^-2$)
par14 Ne III column (in units of $10^{16}$ cm$^-2$)
par15 Mg I column (in units of $10^{16}$ cm$^-2$)
par16 Mg II column (in units of $10^{16}$ cm$^-2$)
par17 Mg III column (in units of $10^{16}$ cm$^-2$)
par18 Si I column (in units of $10^{16}$ cm$^-2$)
par19 Si II column (in units of $10^{16}$ cm$^-2$)
par20 Si III column (in units of $10^{16}$ cm$^-2$)
par21 S I column (in units of $10^{16}$ cm$^-2$)
par22 S II column (in units of $10^{16}$ cm$^-2$)
par23 S III column (in units of $10^{16}$ cm$^-2$)
par24 Ar I column (in units of $10^{16}$ cm$^-2$)
par25 Ar II column (in units of $10^{16}$ cm$^-2$)
par26 Ar III column (in units of $10^{16}$ cm$^-2$)
par27 Ca I column (in units of $10^{16}$ cm$^-2$)
par28 Ca II column (in units of $10^{16}$ cm$^-2$)
par29 Ca III column (in units of $10^{16}$ cm$^-2$)
par30 Fe column (in units of $10^{16}$ cm$^-2$)
par31 Redshift, z
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Next: ismdust: Extinction due to Up: Multiplicative Model Components Previous: hrefl: reflection model   Contents