skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona

Abstract

A turbulent dynamo in spherical geometry with an outer corona is simulated to study the sign of magnetic helicity in the outer parts. In agreement with earlier studies, the sign in the outer corona is found to be opposite to that inside the dynamo. Line-of-sight observations of polarized emission are synthesized to explore the feasibility of using the local reduction of Faraday depolarization to infer the sign of helicity of magnetic fields in the solar corona. This approach was previously identified as an observational diagnostic in the context of galactic magnetic fields. Based on our simulations, we show that this method can be successful in the solar context if sufficient statistics are gathered by using averages over ring segments in the corona separately for the regions north and south of the solar equator.

Authors:
;  [1];  [2]
  1. Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States)
  2. School of Mathematical Sciences and Monash Centre for Astrophysics, Monash University, Clayton, VIC 3800 (Australia)
Publication Date:
OSTI Identifier:
22654410
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 845; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DEPOLARIZATION; EMISSION; HELICITY; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; REDUCTION; SIMULATION; SOLAR CORONA; SPHERICAL CONFIGURATION; SUN; TURBULENCE

Citation Formats

Brandenburg, Axel, Ashurova, Mohira B., and Jabbari, Sarah, E-mail: brandenb@nordita.org. Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona. United States: N. p., 2017. Web. doi:10.3847/2041-8213/AA844B.
Brandenburg, Axel, Ashurova, Mohira B., & Jabbari, Sarah, E-mail: brandenb@nordita.org. Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona. United States. doi:10.3847/2041-8213/AA844B.
Brandenburg, Axel, Ashurova, Mohira B., and Jabbari, Sarah, E-mail: brandenb@nordita.org. Sun . "Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona". United States. doi:10.3847/2041-8213/AA844B.
@article{osti_22654410,
title = {Compensating Faraday Depolarization by Magnetic Helicity in the Solar Corona},
author = {Brandenburg, Axel and Ashurova, Mohira B. and Jabbari, Sarah, E-mail: brandenb@nordita.org},
abstractNote = {A turbulent dynamo in spherical geometry with an outer corona is simulated to study the sign of magnetic helicity in the outer parts. In agreement with earlier studies, the sign in the outer corona is found to be opposite to that inside the dynamo. Line-of-sight observations of polarized emission are synthesized to explore the feasibility of using the local reduction of Faraday depolarization to infer the sign of helicity of magnetic fields in the solar corona. This approach was previously identified as an observational diagnostic in the context of galactic magnetic fields. Based on our simulations, we show that this method can be successful in the solar context if sufficient statistics are gathered by using averages over ring segments in the corona separately for the regions north and south of the solar equator.},
doi = {10.3847/2041-8213/AA844B},
journal = {Astrophysical Journal Letters},
number = 2,
volume = 845,
place = {United States},
year = {Sun Aug 20 00:00:00 EDT 2017},
month = {Sun Aug 20 00:00:00 EDT 2017}
}