Advanced numerical methods for polarized line formation theory a thesis submitted for the award of the degree of Doctor of Philosophy in physics, the Mangalore University L. S. Anusha [Ph.D Thesis]

Thesis Supervisor Prof. Nagendra, K. N.

Doctor of Philosophy Mangalore University, Karnataka 2012

This thesis aims to develop methods to solve radiative transfer (RT) problems in several astrophysical contexts. A major part of the thesis is devoted to develop an understanding of the effects of multi- dimensional (multi-D) RT on the polarized line formation. We consider partial frequency redistribution (PRD) of line radiation in the presence/absence of external magnetic fields. The thesis consists of three parts. In the first part we develop modern numerical methods to solve the line RT equation in one-dimensional (1D) planar and spherical media. In the second part, we formulate and solve the problem of polarized line RT equation in multi-D media. In the third part we focus our attention on realistic modeling of the spectro-polarimetric observations of the linearly polarized spectrum of the Sun (the well known second solar spectrum).