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Related papers: Plasma flows in the cool loop systems

200 papers

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

I report on observations of a set of magnetic loops above a region with late-phase flux emergence taken by IRIS, Hinode and SDO. The loop system consists of many transition region loop threads with size of 5--12\arcsec\ in length and…

Solar and Stellar Astrophysics · Physics 2019-01-09 Zhenghua Huang

A linear analysis based on two-fluid equations in the approximation of a cold plasma, wherein the plasma temperature is assumed to be zero, demonstrates that a two-stream instability occurs in all cases. However, if this were true, the…

Plasma Physics · Physics 2023-06-28 Shinji Koide , Masaaki Takahashi , Rohta Takahashi

Recent observations revealed loop-like structures at very small scales visible in observables that sample transition region (TR) and coronal temperatures. Their formation remains unclear. We study an example of a bipolar system in realistic…

Solar and Stellar Astrophysics · Physics 2023-03-29 M. Skan , S. Danilovic , J. Leenaarts , F. Calvo , M. Rempel

Chromospheric evaporation refers to dynamic mass motions in flare loops as a result of rapid energy deposition in the chromosphere. These have been observed as blueshifts in X-ray and extreme-ultraviolet (EUV) spectral lines corresponding…

Solar and Stellar Astrophysics · Physics 2015-09-23 Y. Li , M. D. Ding , J. Qiu , J. X. Cheng

We describe a new type of dynamical model for hot gas in galaxy groups and clusters in which gas moves simultaneously in both radial directions. Circulation flows are consistent with (1) the failure to observe cooling gas in X-ray spectra,…

Astrophysics · Physics 2009-11-10 William G. Mathews , Fabrizio Brighenti , David A. Buote

Dynamics of hot chromospheric plasma of solar flares is a key to understanding of mechanisms of flare energy release and particle acceleration. A moderate M1.0 class flare of 12 June, 2014 (SOL2014-06-12T21:12) was simultaneously observed…

This analysis begins to explore the complex chromosphere-corona mass cycle using a blend of imaging and spectroscopic diagnostics. Single Gaussian fits to hot emission line profiles (formed above 1MK) at the base of coronal loop structures…

Solar and Stellar Astrophysics · Physics 2015-06-04 Scott W. McIntosh , Hui Tian , Marybeth Sechler , Bart De Pontieu

The relationships among coronal loop structures at different temperatures is not settled. Previous studies have suggested that coronal loops in the core of an active region are not seen cooling through lower temperatures and therefore are…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ignacio Ugarte-Urra , Harry P. Warren , David H. Brooks

We exploit the high spatial resolution and high cadence of the Interface Region Imaging Spectrograph (IRIS) to investigate the response of the transition region and chromosphere to energy deposition during a small flare. Simultaneous…

Solar and Stellar Astrophysics · Physics 2016-09-28 Harry P. Warren , Jeffrey W. Reep , Nicholas A. Crump , Paulo J. A. Simoes

How the solar corona is heated to high temperatures remains an unsolved mystery in solar physics. In the present study we analyse observations of 50 whole active-region loops taken with the Extreme-ultraviolet Imaging Spectrometer (EIS) on…

Solar and Stellar Astrophysics · Physics 2017-06-28 Haixia Xie , Maria S. Madjarska , Bo Li , Zhenghua Huang , Lidong Xia , Thomas Wiegelmann , Hui Fu , Chaozhou Mou

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

Context: Long-period intensity pulsations were recently detected in the EUV emission of coronal loops, and have been attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations…

Solar and Stellar Astrophysics · Physics 2020-02-12 Gabriel Pelouze , Frédéric Auchère , Karine Bocchialini , Clara Froment , Susanna Parenti , Elie Soubrié

We study processes at the transition region between hot (rare) and cold (dense) plasma in the collisionless regime. We use a 3-dimensional electromagnetic particle-in-cell (3-D PIC) relativistic code. Motivated by the transition region in…

Solar and Stellar Astrophysics · Physics 2017-09-25 Marian Karlicky , Frantisek Karlicky

Statistically, the cool loop's footpoints are diagnosed using Si~{\sc iv} resonance lines observations provided by Interface Region Imaging Spectrograph (IRIS). The intensity and Full Width at Half Maximum (FWHM) of the loop's footpoints in…

Solar and Stellar Astrophysics · Physics 2024-01-17 B. Suresh Babu , Pradeep Kayshap , Sharad C. Tripathi , P. Jelinek , B. N. Dwivedi

We study broad red-shifted emission in chromospheric and transition region lines that appears to correspond to a form of post-flare coronal rain. Profiles of Mg II, C II and Si IV lines were obtained using the IRIS instrument before, during…

Solar and Stellar Astrophysics · Physics 2017-08-02 Daniela Lacatus , Philip Judge , Alina Donea

We study the dynamics of plasma along the legs of an arch filament system (AFS) from the chromosphere to the photosphere, observed with high-cadence spectroscopic data from two ground-based solar telescopes: the GREGOR telescope (Tenerife)…

Solar and Stellar Astrophysics · Physics 2020-02-26 S. J. González Manrique , C. Kuckein , A. Pastor Yabar , A. Diercke , M. Collados , P. Gömöry , S. Zhong , Y. Hou , C. Denker

Active region (AR) outflows have been studied in detail since the launch of \textit{Hinode}/EIS and are believed to provide a possible source of mass and energy to the slow solar wind. In this work, we investigate the lower atmospheric…

Solar and Stellar Astrophysics · Physics 2020-11-11 Vanessa Polito , Bart De Pontieu , Paola Testa , David H. Brooks , Viggo Hansteen

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

We study plasma flows along selected coronal loops in NOAA Active Region 10926, observed on 3 December 2006 with Hinode's EUV Imaging Spectrograph (EIS). From the shape of the loops traced on intensity images and the Doppler shifts measured…

Solar and Stellar Astrophysics · Physics 2015-06-05 P. Syntelis , C. Gontikakis , M. K. Georgoulis , C. E. Alissandrakis , K. Tsinganos