English
Related papers

Related papers: Identification of coronal heating events in 3D sim…

200 papers

Much evidence suggests that the solar corona is heated impulsively, meaning that nanoflares may be ubiquitous in quiet and active regions (ARs). Hard X-ray (HXR) observations with unprecedented sensitivity $>$3~keV are now enabled by…

All theories that attempt to explain the heating of the high temperature plasma observed in the solar corona are based on short bursts of energy. The intensities and velocities measured in the cores of quiescent active regions, however, can…

Solar and Stellar Astrophysics · Physics 2015-06-05 Fana M. Mulu-Moore , Amy R. Winebarger , Harry P. Warren

Microflares are small activities in solar low atmosphere, some are in the low corona, and others in the chromosphere. Observations show that some of the microflares are triggered by magnetic reconnection between emerging flux and a…

Solar and Stellar Astrophysics · Physics 2015-06-04 R. -L. Jiang , C. Fang , P. -F. Chen

Nanoflares, short and intense heat pulses within spatially unresolved magnetic strands, are now considered a leading candidate to solve the coronal heating problem. However, the frequent occurrence of nanoflares requires that flare-hot…

Solar and Stellar Astrophysics · Physics 2011-02-11 Fabio Reale , Paola Testa , James A. Klimchuk , Susanna Parenti

The time-dependence of heating in solar active regions can be studied by analyzing the slope of the emission measure distribution cool-ward of the peak. In a previous study we showed that low-frequency heating can account for 0% to 77% of…

Solar and Stellar Astrophysics · Physics 2013-03-20 Jeffrey W. Reep , Stephen J. Bradshaw , James A. Klimchuk

The heating of the solar chromosphere and corona to the observed high temperatures, imply the presence of ongoing heating that balances the strong radiative and thermal conduction losses expected in the solar atmosphere. It has been…

Nanoflares are thought to be one of the prime candidates that can heat the solar corona to its multi-million kelvin temperature. Individual nanoflares are difficult to detect with the present generation instruments, however their presence…

The magnetic field plays a crucial role in heating the solar corona, but the exact energy release mechanism(s) is(are) still unknown. Here, we investigate in detail, the process of magnetic energy release in a situation where two initially…

Astrophysics · Physics 2009-11-10 K. Galsgaard , C. E. Parnell

Determining the preferred spatial location of the energy input to solar coronal loops would be an important step forward towards a more complete understanding of the coronal heating problem. Following on from Sarkar & Walsh (2008) this…

Solar and Stellar Astrophysics · Physics 2009-07-22 Aveek Sarkar , Robert W Walsh

Recent observations of Krucker & Benz (1998) give strong support to Parker's hypothesis (Parker 1988) that small scale dissipative events make the main contribution to quiet Sun coronal heating. They also showed that these small scale…

Astrophysics · Physics 2009-11-06 V. Krasnoselskikh , O. Podladchikova , B. Lefebvre , N. Vilmer

The solar atmosphere is filled with clusters of hot small-scale loops commonly known as Coronal Bright Points (CBPs). These ubiquitous structures stand out in the Sun by their strong X-ray and/or extreme-ultraviolet (EUV) emission for hours…

Solar and Stellar Astrophysics · Physics 2024-06-14 D. Nóbrega-Siverio , F. Moreno-Insertis , K Galsgaard , K. Krikova , L. Rouppe van der Voort , R. Joshi , M. S. Madjarska

The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec) and temporal (5.5s) resolution. The Hi-C observations show in some moss regions…

We present the results of models of impulsively heated coronal loops using the 1-D hydrodynamic Adaptively Refined Godunov Solver (ARGOS) code. The impulsive heating events (which we refer to as "nanoflares") are modeled by discrete pulses…

Solar and Stellar Astrophysics · Physics 2025-09-01 Therese A. Kucera , James A. Klimchuk , Manuel Luna

Nanoflares are believed to be key contributors to heating solar non-flaring active regions, though their individual detection remains challenging. This study uses a data-driven field-aligned hydrodynamic model to examine nanoflare…

Solar and Stellar Astrophysics · Physics 2024-12-31 Biswajit Mondal , James A Klimchuk , Amy R. Winebarger , P. S. Athiray , Jiayi Liu

A full 3-dimensional compressible magnetohydrodynamic (MHD) simulation is conducted to investigate the thermal responses of a coronal loop to the dynamic dissipation processes of MHD waves. When the foot points of the loop are randomly and…

Solar and Stellar Astrophysics · Physics 2018-03-14 Takuma Matsumoto

It is largely agreed that many coronal loops---those observed at a temperature of about 1 MK--- are bundles of unresolved strands that are heated by storms of impulsive nanoflares. The nature of coronal heating in hotter loops and in the…

Solar and Stellar Astrophysics · Physics 2015-05-28 Nicholeen M. Viall , James A. Klimchuk

During the last few decades, the most widely favored models for coronal heating have involved the in situ dissipation of energy, with footpoint shuffling giving rise to multiple current sheets (the "nanoflare" model) or to Alfv{\'e}n waves…

Solar and Stellar Astrophysics · Physics 2022-10-04 Y. -M. Wang

Nanoflares in quiet-Sun regions during solar cycle 24 are studied with the best available plasma diagnostics to derive their energy distribution and contribution to coronal heating during different levels of solar activity. Extreme…

Solar and Stellar Astrophysics · Physics 2022-05-25 Stefan Purkhart , Astrid M. Veronig

X-ray observations of the Sun led Eugene Parker to propose nanoflares as the basic energy-release units that heat the solar corona. Decades later, Solar Orbiter's Extreme Ultraviolet Imager (HRIEUV), operating halfway between Earth and the…

Magnetic energy is required to heat the corona, the outer atmosphere of the Sun, to millions of degrees. We study the nature of the magnetic energy source that is probably responsible for the brightening of coronal loops driven by…

Solar and Stellar Astrophysics · Physics 2018-07-25 L. P. Chitta , H. Peter , S. K. Solanki