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Related papers: Two-Phase Heating in Flaring Loops

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Coronal loops are fundamental building blocks of the solar active regions and the corona. Therefore, a clear understanding of the physics of coronal loops will help us understand the physics of active region heating in particular and…

Solar and Stellar Astrophysics · Physics 2011-02-11 D. Tripathi , H. E. Mason , B. N. Dwivedi , G. Del Zanna , P. R. Young

The study examines the heating profile of hot solar transition region loops, particularly focusing on transient brightenings observed in IRIS 1400{\AA} slit-jaw images. The findings challenge the adequacy of simplistic, singular heating…

Solar and Stellar Astrophysics · Physics 2024-05-15 Shah Mohammad Bahauddin , Stephen J Bradshaw

\textit{Extreme Ultraviolet Explorer} Deep Survey observations of cool stars (spectral type F to M) have been used to investigate the distribution of coronal flare rates in energy and its relation to activity indicators and rotation…

Astrophysics · Physics 2015-06-24 Marc Audard , Manuel Guedel , Jeremy J. Drake , Vinay L. Kashyap

Open-shutter RHESSI observations of 3-15 keV X-rays are found to exhibit active region transient brightenings and microflares at a rate of at least 10 per hour occurring even during the periods of lowest solar activity so far in the…

Astrophysics · Physics 2009-11-07 A. O. Benz , P. Grigis

We present observations of transient active region heating events observed with the Extreme Ultraviolet Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode. This initial investigation focuses on NOAA active region 10940 as…

Due to their characteristic temperature and density, loop structures in active regions (ARs) can be seen bright in extreme ultraviolet (EUV) and soft X-ray images. The semiempirical determination of the three-dimensional (3D) distribution…

Solar and Stellar Astrophysics · Physics 2020-12-16 F. A. Nuevo , C. Mac Cormack , M. López Fuentes , A. M. Vásquez , C. H. Mandrini

Standing long-period (with the periods longer than several minutes) oscillations in large hot (with the temperature higher than 3 MK) coronal loops have been observed as the quasi-periodic modulation of the EUV and microwave intensity…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sanjay Kumar , V. M. Nakariakov , Y. -J. Moon

Brightenings observed in the solar extreme-ultraviolet (EUV) images are generally interpreted as signatures of micro- or nanoflares occurring at the transition region or coronal temperatures. Recent observations with the Extreme Ultraviolet…

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

The soft X-ray emissions of solar flares come mainly from the bright coronal loops at the highest temperatures normally achieved in the flare process. Their ubiquity has led to their use as a standard measure of flare occurrence and energy,…

Solar and Stellar Astrophysics · Physics 2015-06-03 Paulo J. A. Simões , Hugh S. Hudson , Lyndsay Fletcher

Multi-instrument data sets of NOAA AR10938 on Jan. 16, 2007, (e.g., {\emph{Hinode}}, {\it{STEREO}}, {\it{GOES}}, {\it{MLSO}} and {\it{ISOON}} H$\alpha$) are utilized to study the fine structure and evolution of a magnetic loop system…

Solar and Stellar Astrophysics · Physics 2009-11-13 N. -E. Raouafi

We use data at 131, 171, and 304 A from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO) to search for hot flux ropes in 141 M-class and X-class solar flares that occurred at solar longitudes equal to or…

Solar and Stellar Astrophysics · Physics 2015-08-06 A. Nindos , S. Patsourakos , A. Vourlidas , C. Tagikas

To explain the high temperature of the corona, much attention has been paid to the distribution of energy in dissipation events. Indeed, if the event energy distribution is steep enough, the smallest, unobservable events could be the…

Solar and Stellar Astrophysics · Physics 2016-07-06 Vincent Joulin , Éric Buchlin , Jacques Solomon , Chloé Guennou

We explored simultaneous observations of chromospheric evaporation and condensation during the impulsive phase of a C6.7 flare on 9 May 2019. The solar flare was simultaneously observed by multiple instruments, i.e., the New Vacuum Solar…

Solar and Stellar Astrophysics · Physics 2022-02-16 Dong Li , Zhenxiang Hong , Zongjun Ning

In this paper, the cooling of 72 M- and X-class flares is examined using GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the observed total cooling times are compared to the predictions of an analytical 0-D hydrodynamic…

Solar and Stellar Astrophysics · Physics 2014-01-17 Daniel F. Ryan , Phillip C. Chamberlin , Ryan O. Milligan , Peter T. Gallgher

Data from recent numerical simulations of the solar corona and transition region are analysed and the magnetic field connection between the low corona and the photosphere is found to be close to that of a potential field. The fieldline to…

Astrophysics · Physics 2014-10-13 B. V. Gudiksen , Å. Nordlund

One of the outstanding problems in all of space science is uncovering how the solar corona is heated to temperatures greater than 1 MK. Though studied for decades, one of the major difficulties in solving this problem has been unraveling…

Solar and Stellar Astrophysics · Physics 2015-06-15 Nicholeen M. Viall , James A. Klimchuk

We present a detailed X-ray analysis and imaging of stellar coronae of five coronally connected eclipsing binaries, namely, 44 Boo, DV Psc, ER Vul, XY UMa, and TX Cnc. Both components of these binaries are found to be active. The X-ray…

Solar and Stellar Astrophysics · Physics 2022-07-27 Gurpreet Singh , J. C. Pandey

The light curves of solar flares in the impulsive phase are complex in general, indicating that multiple physical processes are involved in. With the GOES (Geostationary Operational Environmental Satellite) observations, we find that there…

Solar and Stellar Astrophysics · Physics 2015-06-16 HAN , Fei-ran , LIU , Si-ming

RHESSI and Hinode observations of a GOES B-class flare are combined to investigate the origin of 15 MK plasma. The absence of any detectable hard X-ray emission coupled with weak blueshifted emission lines (indicating upward velocities…

Solar and Stellar Astrophysics · Physics 2010-03-03 Ryan O. Milligan