SCATTERING POLARIZATION IN THE Ca II INFRARED TRIPLET WITH VELOCITY GRADIENTS

Magnetic field topology, thermal structure, and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the macroscopic vertical velocity field have on the non-magnetic scatt...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2012-05, Vol.751 (1), p.1-13
Main Authors: CARLIN, E. S, MANSO SAINZ, R, ASENSIO RAMOS, A, TRUJILLO BUENO, And J
Format: Article
Language:English
Subjects:
ANISOTROPY
ASTRONOMY
ASTROPHYSICS
ASTROPHYSICS, COSMOLOGY AND ASTRONOMY
CHROMOSPHERE
Earth, ocean, space
Exact sciences and technology
Infrared
Linear polarization
MAGNETIC FIELDS
PLASMA
POLARIZATION
RADIANT HEAT TRANSFER
SCATTERING
Solar atmosphere
Spectral lines
SUN
Topology
TRIPLETS
VELOCITY
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Magnetic field topology, thermal structure, and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the macroscopic vertical velocity field have on the non-magnetic scattering polarization signals, establishing the basis for general cases. We demonstrate that the solar plasma velocity gradients may have a significant effect on the linear polarization produced by scattering in chromospheric spectral lines. In particular, we show the impact of velocity gradients on the anisotropy of the radiation field and on the ensuing fractional alignment of the Ca II levels, and how they can lead to an enhancement of the zero-field linear polarization signals. This investigation remarks on the importance of knowing the dynamical state of the solar atmosphere in order to correctly interpret spectropolarimetric measurements, which is important, among other things, for establishing a suitable zero-field reference case to infer magnetic fields via the Hanle effect.
ISSN:0004-637X
1538-4357
DOI:10.1088/0004-637X/751/1/5