src.Atomic.Opacity.HIbf_CrossSec1

src.Atomic.Opacity.HIbf_CrossSec1(k, wl)[source]

return bound-free cross section of a HI atom in n=k in unit of e-18 cm**2

Parameters

  • k (principle quantum number of HI atom) –

  • wl (wavelength, [\(\AA\)]) –

Notes

from 1, 2.

  • non-LTE ok

  • stimulated emission is not corrected

  • absorption coeff.:

    kbf = nk*shibf*(1.-exp(-hv/kt))*1.e-18 (/cm)

Modification history:

  • k.ichimoto 15 jun.1987, 6 Jan.1992

  • k.ichimoto 19 Feb.1994

  • 2019.9.15 k.ichimoto from IDL ahic.pro

References

1

varnazza et al. (1976) ap.j.suppl. vol.30,1.

2

polynomial fitting for b-f gaunt factor is taken from Carbon & Gingerich (1969) “theory and observation of normal stellar atmosphere” mit press