http://arxiv.org/abs/1805.01211
In this paper an analysis of the absorption line profile at $21$ cm hyperfine transition of hydrogen atom in interstellar medium is carried out. It is shown that in most cases the dominant contribution to the profile formation occurs with the account for the additional field on adjacent resonance for the hydrogen atom at rest. The field acting on neighboring resonances leads to the physical processes which can be explained as the interfering pathways between different transitions. In this case the correction to the optical depth can be introduced. A significant none-Doppler broadening of the line profile is found, the frequency shift is determined also. It is shown that the additional physical processes in atom should be taken into account for the detailed analysis of the absorption line profile and for the accurate determination of optical depth and column densities in hydrogen interstellar medium.
D. Solovyev
Fri, 4 May 18
61/65
Comments: 12 pages