English
Related papers

Related papers: Are constant loop widths an artifact of the backgr…

200 papers

Solar corona, the last main layer of the atmosphere of the Sun, is detectable in the EUV and X-ray. The corona is expanding into space up to millions of kilometers and is observable during the eclipse. The temperature is increasing about…

Solar and Stellar Astrophysics · Physics 2019-04-02 Najmeh Ahmadi , Shervin Parsi

A survey of 28 stars using EUV spectra has been conducted to establish the structure of stellar coronae in active binary systems from the EMD, electron densities, and scale sizes. Observations obtained by the EUVE during 9 years of…

Astrophysics · Physics 2009-11-07 J. Sanz-Forcada , N. S. Brickhouse , A. K. Dupree

We study asymptotic lower and upper bounds for the sizes of constant dimension codes with respect to the subspace or injection distance, which is used in random linear network coding. In this context we review known upper bounds and show…

Combinatorics · Mathematics 2017-12-06 Daniel Heinlein , Sascha Kurz

Small (400 to 4000 km) and short lived (10 to 200 km) extreme ultraviolet (EUV) brightenings, detected by the High Resolution Imager EUV (HRIEUV), have been found to be ubiquitous in the Quiet Sun (QS). Their contribution to coronal heating…

Solar and Stellar Astrophysics · Physics 2025-07-02 A. Dolliou , J. A. Klimchuk , S. Parenti , K. Bocchialini

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

We simulate transverse oscillations in radiatively cooling coronal loops and forward-model their spectroscopic and imaging signatures, paying attention to the influence of background emission. The transverse oscillations are driven at one…

Solar and Stellar Astrophysics · Physics 2021-12-01 Mijie Shi , Tom Van Doorsselaere , Patrick Antolin , Bo Li

It is widely believed that loops observed in the solar atmosphere trace out magnetic field lines. However, the degree to which magnetic field extrapolations yield field lines that actually do follow loops has yet to be studied…

Solar and Stellar Astrophysics · Physics 2018-06-27 Harry P. Warren , Nicholas A. Crump , Ignacio Ugarte-Urra , Xudong Sun , Markus J. Aschwanden , Thomas Wiegelmann

We study the spectrum of loops as a part of a complete network of cosmic strings in flat spacetime. After a long transient regime, characterized by production of small loops at the scale of the initial conditions, it appears that a true…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Vitaly Vanchurin , Ken D. Olum , Alexander Vilenkin

It has been argued that the small perturbations to the homogeneous and isotropic configurations of a canonical scalar field in an expanding universe do not grow. We show that this is not true in general, and clarify the root of the…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Miguel Alcubierre , Axel de la Macorra , Alberto Diez-Tejedor , José M. Torres

In general-relativistic cosmological models, the expansion history, matter content, and geometry are closely intertwined. In this brief paper, we clarify the distinction between the effects of geometry and expansion history on the…

Astrophysics · Physics 2009-11-10 Robert R. Caldwell , Marc Kamionkowski

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

Searches for variations of fundamental constants require accurate measurement errors. There are several potential sources of errors and quantifying each one accurately is essential. This paper addresses one source of uncertainty relating to…

Instrumentation and Methods for Astrophysics · Physics 2022-12-02 Chung-Chi Lee , John K. Webb , Darren Dougan , Vladimir A. Dzuba , Victor V. Flambaum

Aims: Emission line profiles from solar coronal loops exhibit properties that are unexplained by current models. We investigate the non-thermal broadening associated with plasma heating in coronal loops that is induced by magnetic field…

Solar and Stellar Astrophysics · Physics 2020-08-28 D. I. Pontin , H. Peter , L. P. Chitta

We study Euclidean Wilson loops at strong coupling using the AdS/CFT correspondence, where the problem is mapped to finding the area of minimal surfaces in Hyperbolic space. We use a formalism introduced recently by Kruczenski to…

High Energy Physics - Theory · Physics 2015-01-20 Amit Dekel

Srivastava et al. (2010) have observed a highly twisted coronal loop, which was anchored in AR10960 during the period 04:43 UT-04:52 UT on 4 June 2007. The loop length and radius are approximately 80 Mm and 4 Mm, with a twist of 11.5 $\pi$.…

Solar and Stellar Astrophysics · Physics 2015-06-12 A. K. Srivastava , G. J. J. Botha , T. D. Arber , P. Kayshap

Observations of transition region emission in solar active regions represent a powerful tool for determining the properties of hot coronal loops. In this Letter we present the analysis of new observations of active region moss taken with…

Coronal holes are the observational manifestation of the solar magnetic field open to the heliosphere and are of pivotal importance for our understanding of the origin and acceleration of the solar wind. Observations from space missions…

We present estimates of the confusion limit of measurements of the Sunyaev-Zel'dovich effect (SZ) increment near its peak intensity based on Monte Carlo simulations of sub-millimetre observations of galaxy clusters. Specifically, we…

Astrophysics · Physics 2007-05-23 Michael Zemcov , Peter Newbury , Mark Halpern

We study the production of loops in the cosmic string network in the expanding background by means of a numerical simulation exact in the flat-spacetime limit and first-order in the expansion rate. We find an initial regime characterized by…

Astrophysics · Physics 2008-11-26 Ken D. Olum , Vitaly Vanchurin

Motivated by the recent experimental observations of the DNA loop extrusion by protein motors, in this paper we investigate the statistical properties of the growing polymer loops within the ideal chain model. The loop conformation is…

Statistical Mechanics · Physics 2021-04-30 Dmitry Starkov , Vladimir Parfenyev , Sergey Belan