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Related papers: A Comparison of EIT and TRACE Loop Widths

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The structure of the solar corona is dominated by the magnetic field because the magnetic pressure is about four orders of magnitude higher than the plasma pressure. Due to the high conductivity the emitting coronal plasma (visible e.g. in…

Astrophysics · Physics 2009-06-25 T. Wiegelmann , B. Inhester , A. Lagg , S. K. Solanki

The exoplanetary science through direct imaging and spectroscopy will largely expand with the forthcoming development of new instruments at the VLT (SPHERE), Gemini (GPI), Subaru (HiCIAO), and Palomar (Project 1640) observatories. All these…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 P. Martinez , E. Aller-Carpentier , M. Kasper , A. Boccaletti , C. Dorrer , J. Baudrand

Many models for coronal loops have difficulty explaining the observed EUV brightness of the transition region, which is often significantly less than theoretical models predict. This discrepancy has been addressed by a variety of approaches…

Solar and Stellar Astrophysics · Physics 2009-08-24 Bart De Pontieu , Viggo H. Hansteen , Scott W. McIntosh , Spiros Patsourakos

Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal…

Solar and Stellar Astrophysics · Physics 2016-03-23 David H. Brooks , Harry P. Warren

Future missions such as Solar Orbiter (SO), InterHelioprobe, or Solar Probe aim at approaching the Sun closer than ever before, with on board some high resolution imagers (HRI) having a subsecond cadence and a pixel area of about $(80km)^2$…

Astrophysics · Physics 2015-05-13 Véronique Delouille , Pierre Chainais , Jean-François Hochedez

Unknown electric conductivities of human tissues is a common issue in medical engineering. Electrical impedance tomography (EIT) is an imaging modality that can be used to determine these conductivities in vivo from boundary measurements.…

Medical Physics · Physics 2020-02-03 Ville Rimpilainen , Theodoros Samaras , Alexandra Koulouri

Loops are fundamental structures in the magnetized atmosphere of the sun. Their physical properties are crucial for understanding the nature of the solar atmosphere. Transition region loops are relatively dynamic and their physical…

Solar and Stellar Astrophysics · Physics 2024-04-16 Shiyu Liang , Ziyuan Wang , Zhenghua Huang , Hengyuan Wei , Hui Fu , Ming Xiong , Lidong Xia

We have measured line widths in active region coronal loops in order to determine whether the non-thermal broadening is anisotropic with respect to the magnetic field direction. These non-thermal velocities are caused by unresolved fluid…

Solar and Stellar Astrophysics · Physics 2023-08-09 Michael Hahn , Mahboubeh Asgari-Targhi , Daniel Wolf Savin

A new method for automated detection of polar coronal holes is presented. This method, called perimeter tracing, uses a series of 171, 195, and 304 \AA\ full disk images from the Extreme ultraviolet Imaging Telescope (EIT) on SOHO over…

Solar and Stellar Astrophysics · Physics 2015-05-13 Michael S. Kirk , W. Dean Pesnell , C. Alex Young , Shea A. Hess Webber

The relative Doppler velocities and linewidths in a polar coronal hole and the nearby quiet-Sun region have been obtained from the {\it Solar and Heliospheric Observatory} (SOHO)/{\it Coronal Diagnostic Spectrometer} (CDS) observations…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. P. Raju , B. J. I Bromage

The Airborne Infrared Spectrometer (AIR-Spec) offers an unprecedented opportunity to explore the Near Infra-Red (NIR) wavelength range. It has been flown at two total solar eclipses, in 2017 and 2019. The wavelength range of the much…

Solar and Stellar Astrophysics · Physics 2023-03-01 G. Del Zanna , J. Samra , A. Monaghan , C. Madsen , P. Bryans , E. DeLuca , H. Mason , B. Berkey , A. de Wijn , Y. Rivera

Coronal Holes (CHs) are regions of open magnetic field lines, resulting in high speed solar wind. Accurate detection of CHs is vital for space weather prediction. This paper presents an intramethod ensemble for coronal hole detection based…

Solar and Stellar Astrophysics · Physics 2024-11-08 Jeremy A. Grajeda , Laura E. Boucheron , Michael S. Kirk , Andrew Leisner , C. Nick Arge

Recent IRIS observations have revealed a prevalence of intermittent small-scale jets with apparent speeds of 80 - 250 km s$^{-1}$, emanating from small-scale bright regions inside network boundaries of coronal holes. We find that these…

Solar and Stellar Astrophysics · Physics 2016-04-22 Nancy Narang , Rebecca T. Arbacher , Hui Tian , Dipankar Banerjee , Steven R. Cranmer , Ed E. DeLuca , Sean McKillop

We identify coronal holes using a histogram-based intensity thresholding technique and compare their properties to fast solar wind streams at three different points in the heliosphere. The thresholding technique was tested on EUV and X-ray…

Solar and Stellar Astrophysics · Physics 2009-05-13 Larisza D. Krista , Peter T. Gallagher

Decaying active region 10942 is investigated from 4:00-16:00 UT on February 24, 2007 using a suite of EUV observing instruments. Results from Hinode/EIS, STEREO and TRACE show that although the active region has decayed and no sunspot is…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jason Scott , P. C. H. Martens , David McKenzie

Electrical Capacitance Tomography (ECT) is an imaging technique providing the distribution of permittivity in a medium by the mean of electrodes. As for any imaging systems, the reachable spatial resolution is a key parameter. In this paper…

Instrumentation and Detectors · Physics 2015-03-05 Jérôme Lucas , Cédric Margo , Yacine Oussar , Stéphane Holé

The variation of the vector magnetic field along structures in the solar corona remains unmeasured. Using a unique combination of spectropolarimetry and stereoscopy, we infer and compare the vector magnetic field structure and…

Solar and Stellar Astrophysics · Physics 2016-12-14 Thomas A. Schad , Matthew J. Penn , Haosheng Lin , Philip G. Judge

Coronal loops, seen in solar coronal images, are believed to represent emission from magnetic flux tubes with compact cross-sections. We examine the 3D structure of plasma above an active region in a radiative magnetohydrodynamic simulation…

Solar and Stellar Astrophysics · Physics 2022-03-09 A. Malanushenko , M. C. M. Cheung , C. E. DeForest , J. A. Klimchuk , M. Rempel

The characteristic electron densities, temperatures, and thermal distributions of 1MK active region loops are now fairly well established, but their coronal magnetic field strengths remain undetermined. Here we present measurements from a…

Solar and Stellar Astrophysics · Physics 2021-07-14 David H. Brooks , Harry P. Warren , Enrico Landi

The inner regions of the solar corona from 1-2.5 Rsun are poorly sampled both from the ground and space telescopes. A solar eclipse reduces the sky scattered background intensity by a factor of about 10,000 and opens a window to view this…

Instrumentation and Methods for Astrophysics · Physics 2016-12-21 M J Penn , R Baer , R Bosh , D Garrison , R Gelderman , H Hare , F Isberner , L Jensen , S Kovac , M McKay , A Mitchell , M Pierce , A Ursache , J Varsik , D Walter , Z Watson , D Young , the Citizen CATE Team
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