Properties of the second-order moments of the polarization profiles of hydrogen lines.
Abstract
In this paper we give the expressions for the second-order moments of the polarization profiles, for any hydrogen line which is formed in the presence of external electric and magnetic fields. These quantities are directly related to the dispersions of the polarization profiles and are useful whenever the centers-of-gravity method cannot be applied, as in the case of the linear Stark effect or, more generally, when investigating the linear-polarization profiles. An analytical definition of the modulation of the polarization signals is given in order to provide an unambiguous way to estimate the sensitivity of a line to the electric and magnetic fields. Then, relevant properties of the modulations are examined in typical regimes of the external fields.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1995
- Bibcode:
- 1995A&A...300..309C
- Keywords:
-
- MAGNETIC FIELDS;
- POLARIZATION;
- RADIATIVE TRANSFER;
- LINE: PROFILES;
- ATOMIC PROCESSES