Corrected neutral Hydrogen HI flux: m21c

The HI line magnitude m21 has been corrected for self-absorption effect following Heidmann et al (1972), with parameter kappa=0.031. The inclination needed to compute this correction is given as parameter incl. If inclination is higher than 89 deg the maximum correction is limited to -0.82 mag.

Corrected flux at other wavelengths are given in the parameters: bt, it. The measured HI flux is m21.