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Related papers: Thermodynamic Evolution of Solar Flare Supra-arcad…

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We present a study of the spatial and spectral evolution of the loop-top (LT) sources in a sample of 6 flares near the solar limb observed by {\it RHESSI}. A distinct coronal source, which we identify as the LT source, was seen in each of…

Astrophysics · Physics 2009-11-13 Yan Wei Jiang , Siming Liu , Wei Liu , Vahe Petrosian

Quasi-periodic disturbances have been observed in the outer solar atmosphere for many years now. Although first interpreted as upflows (Schrijver et al. (1999)), they have been widely regarded as slow magnetoacoustic waves, due to observed…

Solar and Stellar Astrophysics · Physics 2015-06-05 G. Kiddie , I. De Moortel , G. Del Zanna , S. W. McIntosh , I. Whittaker

Solar flares occur due to the sudden release of energy stored in active-region magnetic fields. To date, the pre-cursors to flaring are still not fully understood, although there is evidence that flaring is related to changes in the…

Solar and Stellar Astrophysics · Physics 2012-02-01 Sophie A. Murray , D. Shaun Bloomfield , Peter T. Gallagher

Sunspots are regions of decreased brightness on the visible surface of the Sun (photosphere) that are associated with strong magnetic fields. They have been found to be locations associated with solar flares, which occur when energy stored…

Solar and Stellar Astrophysics · Physics 2013-01-24 Sophie A. Murray

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\'enic)…

Context. Multi-dimensional solar flare simulations have not yet included detailed analysis of the lower atmospheric responses such as down-flowing chromospheric compressions and chromospheric evaporation processes. Aims. We present an…

Solar and Stellar Astrophysics · Physics 2024-02-02 Malcolm Druett , Wenzhi Ruan , Rony Keppens

Small flares frequently occur in the quiet Sun. Previous studies have noted that they share many common characteristics with typical solar flares in active regions. However, their similarities and differences are not fully understood,…

Solar and Stellar Astrophysics · Physics 2023-05-03 Yuji Kotani , Takako T. Ishii , Daiki Yamasaki , Kenichi Otsuji , Kiyoshi Ichimoto , Ayumi Asai , Kazunari Shibata

The origin of solar transition region redshifts is not completely understood. Current research is addressing this issue by investigating three-dimensional magneto-hydrodynamic models that extend from the photosphere to the corona. By…

Solar and Stellar Astrophysics · Physics 2015-05-28 Pia Zacharias , Sven Bingert , Hardi Peter

Magnetic energy released in the corona by solar flares reaches the chromosphere where it drives characteristic upflows and downflows known as evaporation and condensation. These flows are studied here for the case where energy is…

Solar and Stellar Astrophysics · Physics 2015-06-22 D. W. Longcope

The measured average velocities in solar and stellar spectral lines formed at transition region temperatures have been difficult to interpret. However, realistic three-dimensional radiation magnetohydrodynamics (3D rMHD) models of the solar…

Solar and Stellar Astrophysics · Physics 2018-07-11 P. Zacharias , V. H. Hansteen , J. Leenaarts , M. Carlsson , B. V. Gudiksen

During solar flares, a considerable portion of the flare atmosphere becomes heated; however, the energy deposition process is still unclear, especially in the lower solar atmosphere. Here, we present spectroscopic and imaging observations…

Solar and Stellar Astrophysics · Physics 2026-03-24 Girjesh Gupta , Ananya Rawat , Helen Mason , Robertus Erdélyi

Minimal observational evidence exists for fast transition region (TR) upflows in the presence of cool loops. Observations of such occurrences challenge notions of standard solar atmospheric heating models, as well as their description of…

Solar and Stellar Astrophysics · Physics 2016-01-13 N. B. Orange , D. L. Chesny , H. M. Oluseyi , K. Hesterly , M. Patel , P. R. Champey

We investigate the thermal properties of a solar flare by the observations of soft X-ray Telescope (XRT) on board Hinode and the Atmospheric Image Assembly on board the Solar Dynamics Observatory (SDO/AIA). Our analysis reveals a tenuous…

Solar and Stellar Astrophysics · Physics 2025-10-22 Xiaoyan Xie , Anna Chen , Crisel Suarez , Katharine K. Reeves , Soumya Roy , Christopher S. Moore , Nishu Karna , Joy Velasquez

The Sun offers a convenient nearby laboratory to study the physical processes of particle acceleration and impulsive energy release in magnetized plasmas that occur throughout the universe, from planetary magnetospheres to black hole…

Solar and Stellar Astrophysics · Physics 2011-05-13 Amir Caspi

In strong stellar and solar flares flare loops typically appear during the decay phase, providing an additional contribution to the flare emission and, possibly, obscuring the flare emission. Super-flares, common in active, cool stars,…

Solar and Stellar Astrophysics · Physics 2024-08-06 Kamil Bicz , Robert Falewicz , Petr Heinzel , Małgorzata Pietras , Paweł Preś

Flare kernels are compact features located in the solar chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. An example is presented from a M1.1 class flare observed on 2011 February 16 07:44…

Solar and Stellar Astrophysics · Physics 2015-06-12 Peter Young , George Doschek , Harry Warren , Hiro Hara

X-ray emission provides the most direct diagnostics of the energy-release process in solar flares. Occasionally, a superhot X-ray source is found to be above hot flare loops of ~10 MK temperature. While the origin of the superhot plasma is…

Solar and Stellar Astrophysics · Physics 2022-02-09 Zhenjun Zhou , Rui Liu , Jianqing Sun , Jie Zhang , Mingde Ding , Yuming Wang , Xiaoyu Yu , Lijuan Liu , Jun Cui

Strong solar flares and coronal mass ejections, here defined not only as the bursts of electromagnetic radiation but as the entire process in which magnetic energy is released through magnetic reconnection and plasma instability, emanate…

Solar and Stellar Astrophysics · Physics 2019-05-29 Shin Toriumi , Haimin Wang

Solar flare X-ray emission results from rapidly increasing temperatures and emission measures in flaring active region loops. To date, observations from the X-Ray Sensor (XRS) onboard the Geostationary Operational Environmental Satellite…

Solar and Stellar Astrophysics · Physics 2013-03-07 Daniel F. Ryan , Ryan O. Milligan , Peter T. Gallagher , Brian R. Dennis , A. Kim Tolbert , Richard A. Schwartz , C. Alex Young

We perform Differential Emission Measure (DEM) analysis of an M7.7 flare that occurred on 2012 July 19 and was well observed by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamic Observatory. Using the observational data with…

Solar and Stellar Astrophysics · Physics 2015-06-19 J. Q. Sun , X. Cheng , M. D. Ding