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Active region 10961 was observed over a five day period (2007 July 2-6) by instrumentation on-board STEREO, Hinode, TRACE and SOHO. As it progressed from Sun centre to the solar limb a comprehensive analysis of the EUV, X-ray and magnetic…

Astrophysics · Physics 2009-09-24 Jane B. Noglik , Robert W. Walsh , Rhona C. Maclean

Spatial information from stellar X-ray coronae can be inferred by use of scaling laws from the solar corona. This requires measurement of the physical parameters temperature and density. We concentrate on the newly available density…

Astrophysics · Physics 2009-11-10 J. -U. Ness , M. Güdel , J. H. M. M. Schmitt , M. Audard , A. Telleschi

High resolution spectra from the Hinode EUV Imaging Spectrometer (EIS) have revealed that coronal spectral line profiles are sometimes asymmetric, with a faint enhancement in the blue wing on the order of 100 km/s. These asymmetries could…

Solar and Stellar Astrophysics · Physics 2015-06-11 David H. Brooks , Harry P. Warren

SDO/AIA images the full solar disk in several EUV bands that are each sensitive to coronal plasma emissions of one or more specific temperatures. We observe that when isolated active regions (ARs) are on the disk, full-disk images in some…

Solar and Stellar Astrophysics · Physics 2021-03-10 Talwinder Singh , Alphonse C. Sterling , Ronald L. Moore

The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. Peter , S. Bingert

We investigate intensity variations and energy deposition in five coronal loops in active region cores. These were selected for their strong variability in the AIA/SDO 94 {\AA} intensity channel. We isolate the hot Fe XVIII and Fe XXI…

Solar and Stellar Astrophysics · Physics 2015-06-19 A. C. Cadavid , J. K. Lawrence , D. J. Christian , D. B. Jess , G. Nigro

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

Recent progress in obtaining high spatial resolution images of the solar corona in the extreme-ultraviolet (EUV) with Hinode, TRACE, SDO and recent Hi-C missions and soft X-ray (SXR) bands opened a new avenue in understanding the solar…

Solar and Stellar Astrophysics · Physics 2014-09-16 V. S. Airapetian , J. Allred

We analyze coordinated Hinode XRT and EIS observations of a non-flaring active region to investigate the thermal properties of coronal plasma taking advantage of the complementary diagnostics provided by the two instruments. In particular…

Solar and Stellar Astrophysics · Physics 2015-05-20 Paola Testa , Fabio Reale , Enrico Landi , Ed DeLuca , Vinay Kashyap

Coronal active regions are studied using Hinode/EIS observations in the EUV line Fe XII {\lambda}195.12 by analyzing their line profiles from 2006 December to 2019 December. The period covers the last 2 yr of solar cycle 23 and solar cycle…

Solar and Stellar Astrophysics · Physics 2022-05-24 Maya Prabhakar , K. P Raju

We have expanded upon earlier work that investigates the relative importance of coronal loops with isothermal $versus$ multithermal cross-field temperature distributions. These results are important for determining if loops have…

Solar and Stellar Astrophysics · Physics 2017-05-29 J. T. Schmelz , G. M. Christian , R. A. Chastain

It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have shown that in the solar corona low-FIP elements, such as Fe, Si,…

Solar and Stellar Astrophysics · Physics 2016-06-22 Harry P. Warren , David H. Brooks , George A. Doschek , Uri Feldman

A set of co-aligned high resolution images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) is used to investigate propagating disturbances (PDs) in warm fan loops at the periphery of a non-flaring…

Solar and Stellar Astrophysics · Physics 2015-06-17 Vadim M. Uritsky , Joseph M. Davila , Nicholeen M. Viall , Leon Ofman

We investigate the thermal properties of a solar flare by the observations of soft X-ray Telescope (XRT) on board Hinode and the Atmospheric Image Assembly on board the Solar Dynamics Observatory (SDO/AIA). Our analysis reveals a tenuous…

Solar and Stellar Astrophysics · Physics 2025-10-22 Xiaoyan Xie , Anna Chen , Crisel Suarez , Katharine K. Reeves , Soumya Roy , Christopher S. Moore , Nishu Karna , Joy Velasquez

The bulk of solar coronal radiative loss consists of soft X-ray emission from quasi-static loops at the cores of Active Regions. In order to develop diagnostics for determining the heating mechanism of these loops from observations by…

Astrophysics · Physics 2014-11-18 P. C. H. Martens

Coronal active regions are observed to get fuzzier and fuzzier (i.e. more and more confused and uniform) in harder and harder energy bands or lines. We explain this evidence as due to the fine multi-temperature structure of coronal loops.…

Solar and Stellar Astrophysics · Physics 2015-05-19 Massimiliano Guarrasi , Fabio Reale , Giovanni Peres

We derived the coronal magnetic field, plasma density, and temperature from the observation of polarization and intensity of radio thermal free-free emission using the Nobeyama Radioheliograph (NoRH) and extreme ultraviolet (EUV)…

The plasma parameters such as the electron density and temperature plays a key role in the dynamics of the solar atmosphere. These characteristics are important in solar physics, because they can help to understand the physics in the solar…

Solar and Stellar Astrophysics · Physics 2018-04-12 J. M Rodríguez Gómez , L. Vieira , A. Dal Lago , J. Palacios

The structure of the solar corona is made of magnetic flux tubes or loops. Due to the lack of contrast with their environment, observing and studying coronal loops in the quiet Sun is extremely difficult. In this work we use a differential…

Solar and Stellar Astrophysics · Physics 2022-08-17 C. Mac Cormack , M. López Fuentes , C. H. Mandrini , D. G. Lloveras , A. M. Vásquez

Spicules have been proposed as significant contributors to the mass and energy balance of the corona. While previous observations have provided a glimpse of short-lived transient brightenings in the corona that are associated with spicules,…

Solar and Stellar Astrophysics · Physics 2017-10-19 Bart De Pontieu , Ineke De Moortel , Juan Martinez-Sykora , Scott McIntosh
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