Magnetic Flux and Magnetic Nonpotentiality of Active Regions in Eruptive and Confined Solar Flares

Li, Ting and Chen, Anqin and Hou, Yijun and Veronig, Astrid M. and Yang, Shuhong and Zhang, Jun (2021) Magnetic Flux and Magnetic Nonpotentiality of Active Regions in Eruptive and Confined Solar Flares. The Astrophysical Journal Letters, 917 (2). L29. ISSN 2041-8205

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Abstract

With the aim of understanding how the magnetic properties of active regions (ARs) control the eruptive character of solar flares, we analyze 719 flares of Geostationary Operational Environmental Satellite (GOES) class ≥C5.0 during 2010–2019. We carry out the first statistical study that investigates the flare-coronal mass ejection (CME) association rate as a function of the flare intensity and the AR characteristics that produce the flare, in terms of its total unsigned magnetic flux (ΦAR). Our results show that the slope of the flare–CME association rate with flare intensity reveals a steep monotonic decrease with ΦAR. This means that flares of the same GOES class but originating from an AR of larger ΦAR, are much more likely to be confined. Based on an AR flux as high as 1.0 × 1024 Mx for solar-type stars, we estimate that the CME association rate in X100-class "superflares" is no more than 50%. For a sample of 132 flares ≥M2.0 class, we measure three nonpotential parameters including the length of steep gradient polarity-inversion line (LSGPIL), the total photospheric free magnetic energy (Efree), and the area with large shear angle (AΨ). We find that confined flares tend to have larger values of LSGPIL, Efree, and AΨ compared to eruptive flares. Each nonpotential parameter shows a moderate positive correlation with ΦAR. Our results imply that ΦAR is a decisive quantity describing the eruptive character of a flare, as it provides a global parameter relating to the strength of the background field confinement.

Item Type: Article
Subjects: Middle Asian Archive > Physics and Astronomy
Depositing User: Managing Editor
Date Deposited: 11 May 2023 07:59
Last Modified: 28 Jul 2025 03:43
URI: http://peerreview.go2articles.com/id/eprint/455

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