English
Related papers

Related papers: Flare Induced Photospheric Velocity Diagnostics

200 papers

Solar flares represent one of the most intense forms of solar activity. Understanding the evolution of physical parameters in the solar atmosphere during flares is key to studying flare mechanisms and improving prediction capabilities.…

Solar and Stellar Astrophysics · Physics 2026-05-27 W. Xu , Q. Hao , Z. Zheng , J. Hong , J. Hu , Y. Qiu , C. Li , M. D. Ding , C. Fang

Rapid blue- and red-shifted events (RBEs/RREs) may have an important role in mass-loading and heating the solar corona, but their nature and origin are still debatable. We aim to model these features to learn more about their properties,…

Solar and Stellar Astrophysics · Physics 2023-02-08 S. Danilovic , J. P. Bjørgen , J. Leenaarts , M. Rempel

The asymmetries observed in the line profiles of solar flares can provide important diagnostics of the properties and dynamics of the flaring atmosphere. In this paper the evolution of the Halpha and Ca II 8542 {\AA} lines are studied using…

We analyze a grid of radiative hydrodynamic simulations of solar flares to study the energy balance and response of the atmosphere to nonthermal electron beam heating. The appearance of chromospheric bubbles is one of the most notable…

Solar and Stellar Astrophysics · Physics 2020-05-22 Aaron Reid , Bogdan Zhigulin , Mats Carlsson , Mihalis Mathioudakis

Recent high-cadence flare campaigns by the Interface Region Imaging Spectrograph (IRIS) have offered new opportunities to study rapid processes characteristic of flare energy release, transport, and deposition. Here, we examine high-cadence…

Solar and Stellar Astrophysics · Physics 2025-04-16 Juraj Lörinčík , Vanessa Polito , Graham S. Kerr , Laura A. Hayes , Alexander J. B. Russell

The bulk of the radiative output of a solar flare is emitted from the chromosphere, which produces enhancements in the optical and UV continuum, and in many lines, both optically thick and thin. We have, until very recently, lacked…

Solar and Stellar Astrophysics · Physics 2015-10-07 Graham S. Kerr , Paulo J. A. Simões , Jiong Qiu , Lyndsay Fletcher

We study the temporal evolution of the Na I D1 line profiles in the M3.9 flare SOL2014-06-11T21:03 UT, using high spectral resolution observations obtained with the IBIS instrument on the Dunn Solar Telescope combined with radiative…

Heating signatures from small-scale magnetic reconnection events in the solar atmosphere have proven to be difficult to detect through observations. Numerical models that reproduce flaring conditions are essential in the understanding of…

Solar and Stellar Astrophysics · Physics 2022-03-30 H. Bakke , M. Carlsson , L. Rouppe van der Voort , B. V. Gudiksen , V. Polito , P. Testa , B. De Pontieu

Recent observations from the Interface Region Imaging Spectrograph (IRIS) appear to show impulsive brightenings in high temperature lines, which when combined with simultaneous ground based observations in H$\alpha$, appear co-spatial to…

Solar and Stellar Astrophysics · Physics 2017-02-08 A. Reid , M. Mathioudakis , A. Kowalski , J. G. Doyle , J. C. Allred

The Interface Region Imaging Spectrograph (IRIS) routinely observes the Si IV resonance lines. When analyzing observations of these lines it has typically been assumed they form under optically thin conditions. This is likely valid for the…

Solar and Stellar Astrophysics · Physics 2019-01-30 Graham S. Kerr , Mats Carlsson , Joel C. Allred , Peter R. Young , Adrian N. Daw

We report on radiative hydrodynamic simulations of M dwarf stellar flares and compare the model predictions to observations of several flares. The flares were simulated by calculating the hydrodynamic response of a model M dwarf atmosphere…

Astrophysics · Physics 2009-11-11 Joel C. Allred , Suzanne L. Hawley , William P. Abbett , Mats Carlsson

Numerical models of solar flares typically focus on the behaviour of directly-heated flare models, adopting magnetic field- aligned, plane-parallel methodologies. With high spatial- and spectral-resolution ground-based optical observations…

Solar and Stellar Astrophysics · Physics 2022-09-21 Christopher M. J. Osborne , Lyndsay Fletcher

Acoustic waves are one of the primary suspects besides magnetic fields for the chromospheric heating process to temperatures above radiative equilibrium (RE). We derived the mechanical wave energy as seen in line-core velocities to obtain a…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Beck , E. Khomenko , R. Rezaei , M. Collados

SDO/HMI observations reveal a class of solar flares with substantial energy and momentum impacts in the photosphere, concurrent with white-light emission and helioseismic responses, known as sunquakes. Previous radiative hydrodynamic…

Solar and Stellar Astrophysics · Physics 2023-11-22 Viacheslav Sadykov , John Stefan , Alexander Kosovichev , Joel Allred , Graham S Kerr , Andrey Stejko , Adam Kowalski

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

In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\ge$1000 km s$^{-1}$ and strong…

Solar and Stellar Astrophysics · Physics 2016-05-25 X. Cheng , M. D. Ding

In this paper, we analyze the high-resolution UV spectra for a C1.7 solar flare (SOL2017-09-09T06:51) observed by the \textit{Interface Region Imaging Spectrograph} (\textit{IRIS}). {We focus on the spectroscopic observations at the…

Solar and Stellar Astrophysics · Physics 2020-12-02 Yi-An Zhou , Y. Li , M. D. Ding , Jie Hong , Ke Yu

Results from the Solar Maximum Mission showed a close connection between the hard X-ray and transition region emission in solar flares. Analogously, the modern combination of RHESSI and IRIS data can inform the details of heating processes…

Solar and Stellar Astrophysics · Physics 2016-08-31 Jeffrey W. Reep , Harry P. Warren , Nicholas A. Crump , Paulo J. A. Simoes

Acceleration and transport of high-energy particles and fluid dynamics of atmospheric plasma are interrelated aspects of solar flares. We present here self-consistently combined Fokker-Planck modeling of particles and hydrodynamic…

Solar and Stellar Astrophysics · Physics 2009-09-28 Wei Liu , Vahe Petrosian , John T. Mariska

Solar flares are powerful particle accelerators, and in the accepted standard flare model most of the flare energy is transported from a coronal energy-release region by accelerated electrons which stop collisionally in the chromosphere,…

Solar and Stellar Astrophysics · Physics 2024-06-18 Paulo J. A. Simões , Lyndsay Fletcher , Hugh S. Hudson , Graham S. Kerr , Matt Penn , Karla F. Lopez