A Hot Cusp-shaped Confined Solar Flare

Abstract

We analyze a confined flare that developed a hot cusp-like structure high in the corona (H∼66 Mm). A growing cusp-shaped flare arcade is a typical feature in the standard model of eruptive flares, caused by magnetic reconnection at progressively larger coronal heights. In contrast, we observe a static hot cusp during a confined flare. Despite an initial vertical temperature distribution similar to that in eruptive flares, we observe a distinctly different evolution during the late (decay) phase, in the form of prolonged hot emission. The distinct cusp shape, rooted at locations of non-thermal precursor activity, was likely caused by a magnetic field arcade that kinked near the top. Our observations indicate that the prolonged heating was a result of slow local reconnection and an increased thermal pressure near the kinked apexes due to continuous plasma upflows.

A Solar Magnetic-fan Flaring Arch Heated by Non-thermal Particles and Hot Plasma from an X-ray Jet Eruption

“…by Hernandez-Perez et al (2019). Considering the flare plasma properties that we have presented combined with an extrapolated magnetic field configuration, we discuss how the flare is formed and how it could produce the hot X-ray cusp with strong upflow.…”

“…In the present study, we investigate a limb flare (SOL2014-01-13T21:51M1.3) exhibiting both characteristics of the standard flare (hot apparent cusp) and confined flare (flaring arch footpoint brightening but lacking CME). Hernandez-Perez et al (2019) recently reported complementary observations of this flare using RHESSI and SDO/AIA. We have comprehensively studied this flare using multiwavelength imaging, spectroscopic and stereoscopic analysis, and magnetic field extrapolation.…”

“…But in this scenario, we also expect a longer cooling time in region C since it is also part of the flaring fan loop. Second, there might be a prolonged heating from secondary reconnection at the cusp region after the initial impulsive phase (Qiu & Longcope 2016;Zhu et al 2018). Hernandez-Perez et al (2019 studied the same flare and proposed that there would be slow local reconnection near the kinked loop apex due to the increase of the thermal pressure by continuous plasma upflows.…”

Monitoring and research of high-energy solar flare emissions with GECAM

“…后者同样具 有 多 个 方 向 的 探 测 器, 用 于 测 量 大 视 场 中 的X射 线和伽马射线爆发, 因此同样是太阳耀斑研究的 重要工具. 尤其是近年来, 取得了一系列新成果, 如光变的准周期振荡研究 [56][57][58] 、 日冕环顶源高能 能谱研究 [59] 、 耀斑初始相高能粒子的证据 [60] 等, 为 理 解 耀 斑 的 物 理 过 程 和 改 进 相 应 理 论 提 供 了 新 线 索. Fermi太 阳 数 据 处 理 和 发 布 由 太 阳 高 能 卫 星RHESSI团 组 负 责, 其 耀 斑 能 谱 分 析 也 是 通 过RHESSI的OSPEX软件包完成(详见Fermi solar).…”

Successive occurrences of quasi-circular ribbon flares in a fan-spine-like configuration involving hyperbolic flux tube

“…It is well understood that magnetic field remains at the helm of all the catastrophic processes occurring in the solar atmosphere including flares, as the energy released during flares is supplied from the magnetic energy that is stored in the flaring region prior to the flare (see e.g., Shibata & Magara 2011). Therefore, the pre-flare magnetic configuration plays a crucial role in determining the trigger and subsequent evolution of solar flares and associated eruptive phenomena (e.g., Joshi et al 2015Joshi et al , 2017cHernandez-Perez et al 2019;Mitra et al 2020a;Qiu et al 2020).…”