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Related papers: Inferring X-ray coronal structures from Zeeman-Dop…

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Using multiwavelength imaging observations from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) on 03 May 2012, we present a novel physical scenario for the formation of a temporary X-point in the solar…

Solar and Stellar Astrophysics · Physics 2020-01-08 A. K. Srivastava , Sudheer K. Mishra , P. Jelínek , Tanmoy Samanta , Hui Tian , Vaibhav Pant , P. Kayshap , D. Banerjee , J. G. Doyle , B. N. Dwivedi

We use local stratified shearing-box simulations to elucidate the impact of two-temperature thermodynamics on the thermal structure of coronae in radiatively efficient accretion flows. Rather than treating the coronal plasma as an…

High Energy Astrophysical Phenomena · Physics 2023-11-01 Christopher J. Bambic , Eliot Quataert , Matthew W. Kunz

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

We present a technique that combines Zeeman Doppler imaging (ZDI) principles with a potential field mapping prescription in order to gain more information about the surface field topology of rapid rotators. This technique is an improvement…

Astrophysics · Physics 2007-05-23 G. A. J. Hussain , A. A. van Ballegooijen , M. Jardine , A. Collier Cameron

We present spatially resolved X-ray spectra taken with the EPIC cameras of XMM-Newton of a sample of 17 cooling clusters and three non-cooling clusters for comparison. The deprojected spectra are analyzed with a multi-temperature model,…

We present an ab initio approach to the solar coronal heating problem by modelling a small part of the solar corona in a computational box using a 3D MHD code including realistic physics. The observed solar granular velocity pattern and its…

Astrophysics · Physics 2009-11-10 B. V. Gudiksen , Å. Nordlund

Context. The solar corona is heated to high temperatures of the order of 10^{6} K. The coronal energy budget and specifically possible mechanisms of coronal heating (wave, DC-electric fields, ..) are poorly understood. This is particularly…

Solar and Stellar Astrophysics · Physics 2015-05-20 S. Javadi , J. Buechner , A. Otto , J. C. Santos

The aim of this paper is to study the latitudinal variation in the solar rotation in soft X-ray corona. The time series bins are formed on different latitude regions of the solar full disk (SFD) images that extend from 80 degree South to 80…

Solar and Stellar Astrophysics · Physics 2015-05-18 Satish Chandra , Hari Om Vats , K. N. Iyer

X-ray reverberation echoes are assumed to be produced in the strongly distorted spacetime around accreting supermassive black holes. This signal allows us to spatially map the geometry of the inner accretion flow - a region which cannot yet…

Twisted coronal loops should be ubiquitous in the solar corona. Twisted magnetic fields contain excess magnetic energy, which can be released during magnetic reconnection, causing solar flares. The aim of this work is to investigate…

Solar and Stellar Astrophysics · Physics 2015-01-27 Mykola Gordovskyy , Philippa Browning , Eduard Kontar , Nicolas Bian

Throughout an activity cycle, magnetic structures rise to the stellar surface, evolve and decay. Tracing their evolution on a stellar corona allows us to characterize the X-ray cycles. However, directly mapping magnetic structures is…

Solar and Stellar Astrophysics · Physics 2022-05-25 M. Coffaro , B. Stelzer , S. Orlando

Context: According to theory, high-energy emission from the coronae of cool stars can severely erode the atmospheres of orbiting planets. No observational tests of the long term effects of erosion have yet been made. Aims: To analyze the…

Solar and Stellar Astrophysics · Physics 2010-08-11 J. Sanz-Forcada , I. Ribas , G. Micela , A. M. T. Pollock , D. Garcia-Alvarez , E. Solano , C. Eiroa

We present an analysis of a ~160 ks NuSTAR observation of the nearby bright Seyfert galaxy IC4329A. The high-quality broadband spectrum enables us to separate the effects of distant reflection from the direct coronal continuum, and to…

Determining the nature of emission processes at the heart of quasars is critical for understanding environments of supermassive black holes. One of the key open questions is the origin of long-wavelength emission from radio-quiet quasars.…

Astrophysics of Galaxies · Physics 2025-09-17 M. Rybak , D. Sluse , K. K. Gupta , M. Millon , E. Behar , F. Courbin , J. P. McKean , H. R. Stacey

X-ray observations suggest high compactness of coronae in active galactic nuclei as well as in X-ray binaries. The compactness of the source implies a strong radial dependence in the illumination of the accretion disc. This will, for any…

High Energy Astrophysical Phenomena · Physics 2019-02-20 E. S. Kammoun , V. Domcek , J. Svoboda , M. Dovciak , G. Matt

The origin of the extended soft X-ray emission around nearby highly inclined disk galaxies (often called as X-ray corona) remains uncertain. The emission could arise from volume-filling hot gas and/or its interaction with cool gas.…

Astrophysics of Galaxies · Physics 2020-01-08 Xiaochuan Jiang , Jiangtao Li , Taotao Fang , Wang Q. Daniel

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 estimated the accuracy of coronal magnetic fields derived from radio observations by comparing them to potential field calculations and the DEM measurements using EUV observations. We derived line of sight component of the coronal…

Solar and Stellar Astrophysics · Physics 2016-02-17 Shun Miyawaki , Kazumasa Iwai , Kiyoto Shibasaki , Daikou Shiota , Satoshi Nozawa

Context: The current distribution of planet mass vs. incident stellar X-ray flux supports the idea that photoevaporation of the atmosphere may take place in close-in planets. Integrated effects have to be accounted for. A proper calculation…

Earth and Planetary Astrophysics · Physics 2015-05-28 J. Sanz-Forcada , G. Micela , I. Ribas , A. M. T. Pollock , C. Eiroa , A. Velasco , E. Solano , D. Garcia-Alvarez

Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal dynamic phenomena at all scales. We employ STEREO/COR1 data obtained near maximum of solar activity in December 2012 (Carrington…

Solar and Stellar Astrophysics · Physics 2016-04-05 Maxim Kramar , Vladimir Airapetian , Haosheng Lin