Journal article
The Effect of Thermal Nonequilibrium on Helmet Streamers
The Astrophysical journal, v 916(2), 115
01 Aug 2021
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
Solar loops in which the coronal heating scale is short compared to the loop length are known to be susceptible to thermal nonequilibrium (TNE). We investigate the effects of this process on the largest loops in the corona, those of a helmet streamer. Our numerical study uses a 2.5D MHD code that includes the full magnetic field dynamics as well as the detailed plasma thermodynamics. The simulation model is axisymmetric, consisting of an equatorial streamer belt and two polar coronal holes. As in previous 1D loop studies, we find that TNE occurs in coronal loops with sufficiently large length, but in contrast to these studies, we find that the process also drives substantial magnetic dynamics, especially near the top of the streamer where the plasma beta becomes of order unity. From the simulation results we determine predictions for spectroscopic and imaging observations of both the hot and cool helmet streamer plasma. Simulations are preformed using different scale heights for the heating and different numerical resolution in order to determine the dependence of our findings on these important parameters. We conclude that TNE in streamers may explain several puzzling observations, such as the ubiquitous blueshifts observed at the edges of active regions. We also discuss the implications of our results for the solar wind.
Metrics
Details
- Title
- The Effect of Thermal Nonequilibrium on Helmet Streamers
- Creators
- Michael J. Schlenker - Drexel UniversitySpiro K. Antiochos - NASA, Goddard Space Flight Ctr, Washington, DC 20546 USAPeter J. MacNeice - Goddard Space Flight CenterEmily I. Mason - Goddard Space Flight Center
- Publication Details
- The Astrophysical journal, v 916(2), 115
- Publisher
- Iop Publishing Ltd
- Number of pages
- 18
- Grant note
- NASA SR Program GSFC NASA LWS Program; National Aeronautics & Space Administration (NASA) Drexel University NASA DRIVE Program NASA; National Aeronautics & Space Administration (NASA)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Physics
- Web of Science ID
- WOS:000681456100001
- Scopus ID
- 2-s2.0-85112682583
- Other Identifier
- 991021860751504721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Astronomy & Astrophysics