Collisional effects on the formation of the second solar spectrum of the Sr {\sc ii} $\lambda$4078 line

Abstract

This work aims to provide key elements to gain better understanding of the formation of the second solar spectrum of the Sr II $\lambda$4078 line. We show that in a certain range of hydrogen density, the effect of isotropic collisions between Sr II ions with hydrogen atoms is important in determining the polarization of the Sr II $\lambda$4078 line. The use of an atomic model that neglects the metastable level 4d of Sr II can induce errors of up to 25 \% in the value of the scattering polarization of the solar Sr II $\lambda$4078 line.

Accepted for publication in Astronomy and Astrophysics

References in corpus (3)

• A Substantial Amount of Hidden Magnetic Energy in the Quiet Sun
• Hanle effect in the solar Ba II D2 line: a diagnostic tool for chromospheric weak magnetic fields
• Evidence for collisional depolarization of the \ion{Ba}{ii} $\lambda 4554$ line in the low chromosphere