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Related papers: Modeling X-ray Loops and EUV "Moss" in an Active R…

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Network loops are a common feature in the quiet Sun. The physical processes sustaining their energy budget is still under discussion. We rely on a multi-instrumental (Solar Orbiter/EUI, Solar Orbiter/PHI, IRIS) observation of a six hours…

Solar and Stellar Astrophysics · Physics 2026-03-31 A. Dolliou , H. Peter , S. Mandal , L. P. Chitta , L. Teriaca , Y. Chen , D. Calchetti

We analyze and model an M1.0 flare observed by SDO/AIA and Hinode/EIS to investigate how flare loops are heated and evolve subsequently. The flare is composed of two distinctive loop systems observed in EUV images. The UV 1600 \AA emission…

Solar and Stellar Astrophysics · Physics 2015-06-11 Y. Li , J. Qiu , M. D. Ding

The moss is the area at the footpoint of the hot (3 to 5 MK) loops forming the core of the active region where emission is believed to result from the heat flux conducted down to the transition region from the hot loops. Studying the…

Solar and Stellar Astrophysics · Physics 2012-11-26 Neda Dadashi , Luca Teriaca , Durgesh Tripathi , Sami K. Solanki , Thomas Wiegelmann

Using detrended fluctuation analysis (DFA) and rescaled range (R/S) analysis, we investigate the scaling properties of EUV intensity fluctuations of low-latitude coronal holes (CHs) and neighboring quiet-Sun (QS) regions in signals obtained…

Solar and Stellar Astrophysics · Physics 2020-01-08 Ana Cristina Cadavid , Mari Paz Miralles , Kristine Romich

We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a…

Solar and Stellar Astrophysics · Physics 2014-05-08 F. Chen , H. Peter , S. Bingert , M. C. M. Cheung

The relative amount of high temperature plasma has been found to be a useful diagnostic to determine the frequency of coronal heating on sub-resolution structures. When the loops are infrequently heated, a broad emission measure (EM) over a…

We present observations and analysis of an X1.8 non-eruptive solar flare on 2012 October 23, which is characterized by an extremely large late-phase peak seen in the warm coronal extreme-ultraviolet (EUV) emissions ($\sim$ 3 MK), with the…

Solar and Stellar Astrophysics · Physics 2024-10-25 Shihan Li , Yu Dai , Mingde Ding , Jinhan Guo , Hao Wu

We investigate the scaling properties of the long-range temporal evolution and intermittency of SDO/AIA intensity observations in four solar environments: an active region core, a weak emission region, and two core loops. We use two…

Solar and Stellar Astrophysics · Physics 2016-11-15 Ana Cristina Cadavid , Yeimy J. Rivera , John K. Lawrence , Damian J. Christian , Peter J. Jennings , A. Franco Rappazzo

Studying the Doppler shifts and the temperature dependence of Doppler shifts in moss regions can help us understand the heating processes in the core of the active regions. In this paper we have used an active region observation recorded by…

Solar and Stellar Astrophysics · Physics 2015-06-04 Durgesh Tripathi , Helen E. Mason , James A. Klimchuk

The recent analysis of observations taken with the EIS instrument on Hinode suggests that well constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for…

Solar and Stellar Astrophysics · Physics 2015-06-04 Harry P. Warren , Amy R. Winebarger , David H. Brooks

We present a study of the frequency of transient brightenings in the core of solar active regions as observed in the Fe XVIII line component of AIA/SDO 94 A filter images. The Fe XVIII emission is isolated using an empirical correction to…

Solar and Stellar Astrophysics · Physics 2015-06-18 Ignacio Ugarte-Urra , Harry P. Warren

Recent observations in extreme-ultraviolet (EUV) wavelengths reveal an EUV late phase in some solar flares that is characterized by a second peak in warm coronal emissions ($\sim3$~MK) several tens of minutes to a few hours after the soft…

Solar and Stellar Astrophysics · Physics 2018-05-02 Yu Dai , Mingde Ding

We search for EUV brightenings in TRACE 171 {\AA} images and HXR bursts observed during failed eruptions. We expect that if an eruption is confined due to interaction with overlying magnetic structures then we should observe effects…

Solar and Stellar Astrophysics · Physics 2015-06-11 A. Netzel , T. Mrozek , S. Kolomanski , S. Gburek

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…

A solar flare is composed of impulsive energy release events by magnetic reconnection, which forms and heats flare loops. Recent studies have revealed a two-phase evolution pattern of UV 1600\AA\ emission at the feet of these loops: a rapid…

Solar and Stellar Astrophysics · Physics 2013-09-16 Jiong Qiu , Zoe Sturrock , Dana W. Longcope , James A. Klimchuk , Wen-Juan , Liu

This paper investigates a quiescent (non-flaring) active region observed on July 13, 2010 in EUV, SXR, and HXRs to search for a hot component that is speculated to be a key signature of coronal heating. We use a combination of RHESSI…

Solar and Stellar Astrophysics · Physics 2019-05-15 Shin-nosuke Ishikawa , Sam Krucker

Coronal loops are plasma structures in the solar atmosphere with temperatures reaching millions of Kelvin, shaped and sustained by the magnetic field. However, their morphology and fundamental nature remain subjects of debate. By studying…

Solar and Stellar Astrophysics · Physics 2026-01-14 N. Vasantharaju , H. Peter , L. P. Chitta , S. Mandal

In addition to X-rays, extreme ultraviolet (EUV) rays radiated from solar flares can cause serious problems, such as communication failures and satellite drag. Therefore, methods for forecasting EUV dynamic spectra during flares are…

Solar and Stellar Astrophysics · Physics 2020-05-14 Toshiki Kawai , Shinsuke Imada , Shohei Nishimoto , Kyoko Watanabe , Tomoko Kawate

We study the extreme-ultraviolet (EUV) emissions modulated by leaky fast sausage modes (FSMs) in solar active region loops and examine their observational signatures via spectrometers like EIS. After computing fluid variables of leaky FSMs…

Solar and Stellar Astrophysics · Physics 2019-10-09 Mijie Shi , Bo Li , Zhenghua Huang , Shao-Xia Chen

The detection of excess of soft X-ray or Extreme Ultraviolet (EUV) radiation, above the thermal contribution from the hot intracluster medium (ICM), has been a controversial subject ever since the initial discovery of this phenomenon. We…