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Related papers: Numerical Study of a Propagating Non-Thermal Micro…

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We consider particle acceleration to high energy via diffusive shock acceleration in a simple, self-consistent shock in jet model for blazars. Electrons are assumed to be accelerated at a shock front in relativistic jets and radiate…

Astrophysics · Physics 2007-05-23 F. M. Rieger , J. G. Kirk , A. Mastichiadis

Solar flares show remarkable variety of the energy partitioning between thermal and nonthermal components. Those with a prominent nonthermal component but only a modest thermal one are particularly well suited to study the direct effect of…

Solar and Stellar Astrophysics · Physics 2020-02-26 Galina G. Motorina , Gregory D. Fleishman , Eduard P. Kontar

We have developed a general framework for modeling gyrosynchrotron and free-free emission from solar flaring loops and used it to test the premise that 2D maps of source parameters, particularly magnetic field, can be deduced from spatially…

Solar and Stellar Astrophysics · Physics 2015-06-15 Dale E. Gary , Gregory D. Fleishman , Gelu M. Nita

Recent observations from {\em RHESSI} have revealed that the number of non-thermal electrons in the coronal part of a flaring loop can exceed the number of electrons required to explain the hard X-ray-emitting footpoints of the same flaring…

Solar and Stellar Astrophysics · Physics 2015-06-18 E. P. Kontar , N. H. Bian , A. G. Emslie , N. Vilmer

This study explores the impact of a turbulent scattering mechanism, akin to those influencing solar and galactic cosmic rays propagating in the interplanetary medium, on the population of suprathermal electrons in the solar wind. We employ…

Nonthermal sources located above bright flare arcades, referred to as the "above-the-loop-top" sources, have been often suggested as the primary electron acceleration site in major solar flares. The X8.2 limb flare on 2017 September 10…

Solar and Stellar Astrophysics · Physics 2021-03-03 Bin Chen , Marina Battaglia , Säm Krucker , Katharine K. Reeves , Lindsay Glesener

The X8.2-class limb flare on September 10, 2017 is among the best studied solar flare events owing to its great similarity to the standard flare model and the broad coverage by multiple spacecraft and ground-based observations. These…

Solar and Stellar Astrophysics · Physics 2022-06-29 Xiaocan Li , Fan Guo , Bin Chen , Chengcai Shen , Lindsay Glesener

Hot magnetic stars often exhibit incoherent circularly polarized radio emission thought to arise from gyro-synchrotron emission by energetic electrons trapped in the circumstellar magnetosphere. Theoretical scalings for electron…

Solar and Stellar Astrophysics · Physics 2023-08-16 B. Das , S. P. Owocki

We investigate how the magnetic loop length of solar flares relates to the timing between their thermal and nonthermal emission signatures. Our study analyzes a sample of 96 C-, M-, and X-class flares observed between 2013 and 2015 with…

Solar and Stellar Astrophysics · Physics 2026-02-24 S. M. Perriyil , S. S. Sadangaya , C. G. Giménez de Castro , P. J. A. Simões

A multi-wavelength spatial and temporal analysis of solar high energy electrons is conducted using the August 20, 2002 flare of an unusually flat (gamma=1.8) hard X-ray spectrum. The flare is studied using RHESSI, Halpha, radio, TRACE, and…

Astrophysics · Physics 2008-11-26 J. Kasparova , M. Karlicky , E. P. Kontar , R. A. Schwartz , B. R. Dennis

Quasi-periodic propagating intensity disturbances have been observed in large coronal loops in EUV images over a decade, and are widely accepted to be slow magnetosonic waves. However, spectroscopic observations from Hinode/EIS revealed…

Solar and Stellar Astrophysics · Physics 2015-11-04 X. Fang , D. Yuan , T. Van Doorsselaere , R. Keppens , C. Xia

The expansion of hot electrons in flaring magnetic loops is crucial to understanding the dynamics of solar flares. In this paper we investigate, for the first time, the transport of hot electrons in a magnetic mirror field based on a 1-D…

Space Physics · Physics 2020-01-08 Jicheng Sun , Xinliang Gao , Yangguang Ke , Quanming Lu , Xueyi Wang , Shui Wang

We study the electron energy spectra of two powerful solar flares SOL2003-10-28T 11:06:16 (GOES class X17.2) and SOL2002-07-23T00:18:16 (X4.8) on the basis of HXR and gamma-ray spectra obtained from RHESSI data. Electron-electron (e-e)…

Solar and Stellar Astrophysics · Physics 2020-12-16 I. D. Oparin , Yu. E. Charikov , E. P. Ovchinnikova , A. N. Shabalin

We have performed microwave diagnostics of the magnetic field strengths in solar flare loops based on the theory of gyrosynchrotron emission. From Nobeyama Radioheliograph observations of three flare events at 17 and 34 GHz, we obtained the…

Solar and Stellar Astrophysics · Physics 2020-06-30 Rui Zhu , Baolin Tan , Yingna Su , Hui Tian , Yu Xu , Xingyao Chen , Yongliang Song , Guangyu Tan

A circular ribbon flare SOL2014-12-17T04:51 is studied using the 17/34 GHz maps from the Nobeyama Radioheliograph (NoRH) along with (E)UV and magnetic data from the Solar Dynamics Observatory (SDO). We report the following three findings as…

Solar and Stellar Astrophysics · Physics 2020-09-28 Jeongwoo Lee , Stephen M. White , Xingyao Chen , Yao Chen , Hao Ning , Bo Li , Satoshi Masuda

We present a detailed examination on the coronal nonthermal emissions during the preflare phase of the X4.8 flare that occurred on 2002 July 23. The microwave (17 GHz and 34 GHz) data obtained with Nobeyama Radioheliograph, at Nobeyama…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ayumi Asai , Hiroshi Nakajima , Masumi Shimojo , Takaaki Yokoyama , Satoshi Masuda , Sam Krucker

The excess broadening of high-temperature spectral lines, long observed near the tops of flare arcades, is widely considered to result from magnetohydrodynamic (MHD) turbulence. According to different theories, plasma turbulence is also…

Solar and Stellar Astrophysics · Physics 2024-07-18 William Ashfield , Vanessa Polito , Sijie Yu , Hannah Collier , Laura Hayes

Optically thick non-thermal synchrotron sources notably produce linear polarization vectors being parallel to projected magnetic field lines on the observer's screen, although they are perpendicular in well-known optically thin cases. To…

High Energy Astrophysical Phenomena · Physics 2024-09-04 Yuh Tsunetoe , Tomohisa Kawashima , Ken Ohsuga , Shin Mineshige

The results of the microwave observations of the Sun made with the RATAN-600 have shown the existence of many types of spectral peculiarities in polarized emission of active regions, which produce powerful flares. These phenomena happen at…

Particle acceleration is one of the most significant features that are ubiquitous among space and cosmic plasmas. It is most prominent during flares in the case of the Sun, with which huge amount of electromagnetic radiation and high-energy…

Solar and Stellar Astrophysics · Physics 2014-05-15 Noriyuki Narukage , Masumi Shimojo , Taro Sakao