Title: Reverse Current Model for Coronal Mass Ejection Cavity Formation

Abstract

In this work, we present a new model for explaining the three-part structure of coronal mass ejections (CMEs). The model proposes that the cavity in a CME forms because a rising electric current in the core prominence induces an oppositely directed electric current in the background plasma; this eddy current is required to satisfy the frozen-in magnetic flux condition in the background plasma. The magnetic force between the inner-core electric current and the oppositely directed induced eddy current propels the background plasma away from the core, creating a cavity and a density pileup at the cavity edge. The cavity radius saturates when an inward restoring force from magnetic and hydrodynamic pressure in the region outside the cavity edge balances the outward magnetic force. The model is supported by (i) laboratory experiments showing the development of a cavity as a result of the repulsion of an induced reverse current by a rising inner-core flux-rope current, (ii) 3D numerical magnetohydrodynamic (MHD) simulations that reproduce the laboratory experiments in quantitative detail, and (iii) an analytic model that describes cavity formation as a result of the plasma containing the induced reverse current being repelled from the inner core. This analytic model offers broad applicabilitymore » because the predicted cavity widths are relatively independent of both the current injection mechanism and the injection timescale.« less

Authors:

Haw, Magnus A.  ^[1];

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Wongwaitayakornkul, Pakorn  ^[1];

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Li, Hui  ^[2];

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Bellan, Paul M.  ^[1]

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• Search DOE PAGES for ORCID "0000-0002-0886-8782"
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+ Show Author Affiliations

1. California Inst. of Technology (CalTech), Pasadena, CA (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

2018-07-31

Research Org.:

California Institute of Technology (CalTech), Pasadena, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); US Air Force Office of Scientific Research (AFOSR); National Science Foundation (NSF)

OSTI Identifier:

1574936

Grant/Contract Number:  

FG02-04ER54755; SC0010471

Resource Type:

Accepted Manuscript

Journal Name:

The Astrophysical Journal. Letters

Additional Journal Information:

Journal Volume: 862; Journal Issue: 2; Journal ID: ISSN 2041-8213

Publisher:

Institute of Physics (IOP)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; methods: laboratory: atomic; Sun: corona; Sun: coronal mass ejections (CMEs); Sun: filaments, prominences; Sun: magnetic fields