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Related papers: Observing coronal nanoflares in active region moss

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We present the results of 1D hydrodynamic simulations of coronal loops which are subject to nanoflares, caused by either in-situ thermal heating, or non-thermal electrons (NTE) beams. The synthesized intensity and Doppler shifts can be…

Solar and Stellar Astrophysics · Physics 2018-04-18 V. Polito , P. Testa , J. Allred , B. De Pontieu , M. Carlsson , T. M. D. Pereira , M. Gošić , F. Reale

The expansion of coronal loops in the transition region may considerably influence the diagnostics of the plasma emission measure. The cross sectional area of the loops is expected to depend on the temperature and pressure, and might be…

Solar and Stellar Astrophysics · Physics 2015-06-18 M. Guarrasi , F. Reale , S. Orlando , A. Mignone , J. A. Klimchuk

Despite decades of studying the Sun, the coronal heating problem remains unsolved. One fundamental issue is that we do not know the spatial scale of the coronal heating mechanism. At a spatial resolution of 1000 km or more it is likely that…

Solar and Stellar Astrophysics · Physics 2012-06-07 David H. Brooks , Harry P. Warren , Ignacio Ugarte-Urra

Coronal upflows at the edges of active regions (AR), which are a possible source of slow solar wind, have been found to connect with dynamics in the transition region. To infer at what scale transition region dynamics connect to AR upflows,…

Solar and Stellar Astrophysics · Physics 2021-09-08 Zhenghua Huang , Lidong Xia , Hui Fu , Zhenyong Hou , Ziyuan Wang

To understand the mechanism of coronal heating, it is crucial to derive the contribution of small-scale flares, the so-called nanoflares, to the heating up of the solar corona. To date, several studies have tried to derive the occurrence…

Solar and Stellar Astrophysics · Physics 2021-01-06 Toshiki Kawai , Shinsuke Imada

We present high-resolution, high-cadence observations of six, fine-scale, on-disk jet-like events observed by the High-resolution Coronal Imager 2.1 (Hi-C 2.1) during its sounding-rocket flight. We combine the Hi-C 2.1 images with images…

We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated into heating by…

Solar and Stellar Astrophysics · Physics 2016-10-12 F. Reale , S. Orlando , M. Guarrasi , A. Mignone , G. Peres , A. W. Hood , E. R. Priest

Recent simulations of solar active regions have shown that it is possible to reproduce both the total intensity and the general morphology of the high temperature emission observed at soft X-ray wavelengths using static heating models.…

Astrophysics · Physics 2011-02-11 Harry P. Warren , Amy R. Winebarger

The content of coronal material in the quiet Sun is not constant as soft X-ray and high-temperature EUV line observations have shown. New material, probably heated and evaporated from the chromosphere is occasionally injected even in the…

Astrophysics · Physics 2007-05-23 Arnold O. Benz , Sam Krucker

We report on the first Interface Region Imaging Spectrograph (IRIS) study of cool transition region loops. This class of loops has received little attention in the literature. A cluster of such loops was observed on the solar disk in active…

Solar and Stellar Astrophysics · Physics 2015-09-09 Zhenghua Huang , Lidong Xia , Bo Li , Maria S. Madjarska

Small-scale magnetic reconnection processes, in the form of nanoflares, have become increasingly hypothesized as important mechanisms for the heating of the solar atmosphere, for driving propagating disturbances along magnetic field lines…

When magnetic flux emerges from beneath the photosphere it displaces the preexisting field in the corona, and a current sheet generally forms at the boundary between the old and new magnetic domains. Reconnection in the current sheet…

Solar and Stellar Astrophysics · Physics 2015-06-17 Lucas A. Tarr , Dana W. Longcope , David E. McKenzie , Keiji Yoshimura

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

We report a quasi-periodic pulsation (QPP) event simultaneously detected from the spatial displacements of coronal loop at both EUV images and microwave emission during the preflare phase of a C1.1 flare on 2016 March 23. Using the motion…

Solar and Stellar Astrophysics · Physics 2020-04-22 Dong Li , Ying Li , Lei Lu , Qingmin Zhang , Zongjun Ning , Sergey Anfinogentov

We use UV spectral observations of active regions with the Interface Region Imaging Spectrograph (IRIS) to investigate the properties of the coronal FeXII 1349.4A emission at unprecedented high spatial resolution (~0.33"). We find that by…

Solar and Stellar Astrophysics · Physics 2016-08-17 Paola Testa , Bart De Pontieu , Viggo Hansteen

Coronal waves, significant solar phenomena, act as diagnostic tools for scientists studying solar atmosphere properties. Here, we present a novel observation detailing how a coronal wave event, associated with an X5.0 class flare,…

It has been proposed that the million degree temperature of the corona is due to the combined effect of barely-detectable energy releases, so called nanoflares, that occur throughout the solar atmosphere. Alas, the nanoflare density and…

Solar and Stellar Astrophysics · Physics 2015-05-27 M. R. Bareford , P. K. Browning , R. A. M. Van der Linden

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

We perform direct numerical simulations of an externally driven two-dimensional magnetohydrodynamic system over extended periods of time to simulate the dynamics of a transverse section of a solar coronal loop. A stationary and large-scale…

Astrophysics · Physics 2009-10-30 Pablo Dmitruk , Daniel O. Gomez

The energy input into the lower solar corona by flare evaporation events has been modeled according to the available observations for quiet regions. The question is addressed whether such heating events can provide the observed average…

Astrophysics · Physics 2008-11-26 U. Mitra-Kraev , A. O. Benz
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