Anomalous circular polarization profiles in the He I 1083.0 nm multiplet from solar spicules

TL;DR

This paper presents spectropolarimetric observations of solar spicules revealing asymmetric Stokes V profiles in the He I 1083 nm multiplet, modeled with two magnetic components and atomic orientation, highlighting complex magnetic and atomic effects.

Contribution

It introduces the first detailed modeling of asymmetric Stokes V profiles in solar spicules involving multiple magnetic components and atomic orientation effects.

Findings

Detection of extremely asymmetric Stokes V profiles in spicules

Modeling with two magnetic components along the line of sight

Identification of atomic orientation influencing polarization signals

Abstract

We report Stokes vector observations of solar spicules and a prominence in the He I 1083 nm multiplet carried out with the Tenerife Infrared Polarimeter. The observations show linear polarization profiles that are produced by scattering processes in the presence of a magnetic field. After a careful data reduction, we demonstrate the existence of extremely asymmetric Stokes V profiles in the spicular material that we are able to model with two magnetic components along the line of sight, and under the presence of atomic orientation in the energy levels that give rise to the multiplet. We discuss some possible scenarios that can generate the atomic orientation in spicules. We stress the importance of spectropolarimetric observations across the limb to distinguish such signals from observational artifacts.