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arXiv 2602.01323astro-ph.SRastro-ph.HE
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日冕源中MeV峰值电子的宿主

MeV-peaked electrons in a coronal source of a solar flare

New Jersey Institute of Technology(新泽理工学院)

Gregory D. Fleishman, Ivan Oparin, Gelu M. Nita, Bin Chen, Sijie Yu, Dale E. Gary

AI总结:

研究通过联合分析费米和EOVSA数据,确定日珥中MeV峰值电子群体的位置,揭示其形成与磁能释放及传输效应的关系。

摘要:

日珥爆发迅速释放大量自由磁能,产生大量高能带电粒子,包括离子和电子。这些粒子在太阳磁场中辐射微波,或在遇到物质时产生X射线和γ射线而被检测到。对日珥中γ射线的分析揭示出一个主导于MeV能量的连续成分,这与已研究的由爆发加速电子产生的X射线连续体不同。直到现在,这个神秘的MeV成分的起源、精确的空间位置和范围仍不清楚。如果它是由轫廷辐射产生的,那么这种γ射线成分需要一个异常的电子群体,其能量峰值在数MeV左右。在这里,我们报告了2017年9月10日日珥爆发中MeV峰值电子群体的联合研究,结合费米MeVγ射线数据和EOVSA空间分辨微波成像光谱数据。我们证明了来自峰值MeV分布的微波光谱具有与已知电子群体产生的光谱明显不同的形状。我们检查了日珥的微波地图,并确定了一个演化的区域,其中测量的微波光谱与理论上预期的MeV峰值群体光谱相匹配,从而确定了该MeV成分所在的位置。这些位置位于日冕体积中,靠近检测到显著磁能释放和批量电子加速的区域,这表明传输效应在形成该群体中起关键作用。

英文摘要:

Analysis of γ-rays in solar flares has suggested a distinct continuum component dominating at MeV energies, which differs from the well-studied X-ray continuum produced by flare-accelerated electrons with spectra steeply falling with energy. The origin, precise spatial location, and extent of this mysterious MeV component have been unknown up to now. If it is produced by bremsstrahlung, such a γ-ray component requires an unusual population of electrons peaked at a few MeV. Here we report a joint study of this MeV-peaked electron population in the 2017-Sep-10 solar flare with Fermi MeV γ-ray data and EOVSA spatially resolved microwave imaging spectroscopy data. We demonstrate that the microwave spectrum from the MeV-peaked distribution has a distinctly different shape from that produced by the electrons with falling energy spectrum. We inspected microwave maps of the flare and identified an evolving area where the measured microwave spectra matched the theoretically expected one for the MeV-peaked population, thus pinpointing the site where this MeV component resides. The locations are in a coronal volume adjacent to the region where prominent release of magnetic energy and bulk electron acceleration were detected, which implies that transport effects play a key role in forming this population.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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