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Related papers: Solar UV and X-Ray Spectral Diagnostics

200 papers

There is a pressing need to model X-ray Ultra-Violet (XUV: 1-30 nm) stellar irradiances, given the scarcity of current measurements. One of the measurable effects of a stellar cycle is the significant (more than one order of magnitude)…

Solar and Stellar Astrophysics · Physics 2025-04-14 E. Deliporanidou , G. Del Zanna , T. N. Woods , D. Woodraska

Solar images taken simultaneously at different wavelengths in the EUV are widely used for understanding structures such as flares, coronal holes, loops, etc. The line-of-sight integration and the finite spectral resolution of EUV…

Astrophysics · Physics 2009-11-13 T. Dudok de Wit , F. Auchere

The opportunities of the application of the recently proposed approach in optical emission spectroscopy of non-equilibrium plasmas have been studied. The approach consists of several methods of the determination of {\em absolute} particle…

Plasma Physics · Physics 2007-05-23 B. P. Lavrov , A. S. Mikhailov

Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations…

Solar and Stellar Astrophysics · Physics 2009-07-22 Harry P. Warren , David H. Brooks

We present a new method for performing differential emission measure (DEM) inversions on narrow-band EUV images from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). The method yields positive definite…

Solar and Stellar Astrophysics · Physics 2015-07-15 Mark C. M. Cheung , P. Boerner , C. J. Schrijver , P. Testa , F. Chen , H. Peter , A. Malanushenko

Most observations of the solar corona beyond 2 Rs consist of broadband visible light imagery from coronagraphs. The associated diagnostics mainly consist of kinematics and derivations of the electron number density. While the measurement of…

Solar and Stellar Astrophysics · Physics 2023-06-28 Auchère , F. , Berghmans , D. , Dumesnil , C. , Halain , J. -P. , Mercier , R. , Rochus , P. , Delmotte , F. , François , S. , Hermans , A. , Hervier , V. , Kraaikamp , E. , Meltchakov , E. , Morinaud , G. , Philippon , A. , Smith , P. J. , Stegen , K. , Verbeeck , C. , Zhang , X. Y. , Andretta , V. , Abbo , L. , Buchlin , E. , Frassati , F. , Gissot , S. , Gyo , M. , Harra , L. , Jerse , G. , Landini , F. , Mierla , M. , Nicula , B. , Parenti , S. , Renotte , E. , Romoli , M. , Russano , G. , Sasso , C. , Schühle , U. , Schmutz , W. , Soubrié , E. , Susino , R. , Teriaca , L. , West , M. , Zhukov , A. N

Daily differential emission measure (DEM) distributions of the solar corona are derived from spectra obtained by the Extreme-ultraviolet Variability Experiment (EVE) over a 4-year period starting in 2010 near solar minimum and continuing…

Solar and Stellar Astrophysics · Physics 2020-09-16 Samuel J. Schonfeld , Stephen M. White , Rachel A. Hock-Mysliwiec , R. T. James McAteer

High-resolution tunable laser spectroscopy is used to measure time-resolved absorption spectra for ten neutral uranium transitions and six singly-ionized transitions in a laser produced plasma. Spectral lineshapes are analyzed to determine…

We review the importance of recent UV observations of solar system targets and discuss the need for further measurements, instrumentation and laboratory work in the coming decade. In the past decade, numerous important advances have been…

A differential emission measure (DEM) method is used to evaluate the relationship of the electron density and temperature before and after a coronal rain event during an active sun over the period from 20:10 UT on October 6 to 02:10 on…

Solar and Stellar Astrophysics · Physics 2021-10-05 Z. M. Vashalomidze , T. V. Zaqarashvili , V. D. Kukhianidze

The present report briefly reviews the basic features of the current strategy for the protection against the health harms caused by solar ultraviolet (UV, 295 - 400 nm). The emphasis has been made upon the erythema as being the best-studied…

Tissues and Organs · Quantitative Biology 2020-06-26 Boyan H Petkov

We report multi-wavelength observations of four solar flares on 2014 July 07. We firstly select these flares according to the soft X-ray (SXR) and extreme ultraviolet (EUV) emissions recorded by the Extreme Ultraviolet Variability…

Solar and Stellar Astrophysics · Physics 2021-05-05 Dong Li , Alexander Warmuth , Lei Lu , Zongjun Ning

The X-ray and extreme-ultraviolet (EUV) emissions from the low-mass stars significantly affect the evolution of the planetary atmosphere. However, it is, observationally difficult to constrain the stellar high-energy emission because of the…

Solar and Stellar Astrophysics · Physics 2021-12-11 Munehito Shoda , Shinsuke Takasao

The Solar Aspect Monitor (SAM) is a pinhole camera on the Extreme-ultraviolet Variability Experiment (EVE) aboard the Solar Dynamics Observatory (SDO). SAM projects the solar disk onto the CCD through a metallic filter designed to allow…

Solar and Stellar Astrophysics · Physics 2016-05-27 C. Y. Lin , S. M. Bailey , A. Jones , D. Woodraska , A. Caspi , T. N. Woods , F. G. Eparvier , S. R. Wieman , L. V. Didkovsky

Collective X-ray Thomson scattering has become a versatile tool for the diagnostics of dense plasmas. Assuming homogeneous density and temperature throughout the target sample, these parameters can be determined directly from the plasmon…

X-ray emission from cool stars is an important tracer for stellar activity. The X-ray luminosity reflects different levels of activity and covers four orders of magnitude in stars of spectral types M-F. Low spectral resolution provided by…

Astrophysics · Physics 2009-11-10 J. -U. Ness

We present a study of the differential emission measure (DEM) of a `quiet Sun' area observed in the extreme ultraviolet at normal incidence by the Coronal Diagnostic Spectrometer (CDS) on the SOHO spacecraft. The data used for this work…

Astrophysics · Physics 2009-11-10 A. C. Lanzafame , D. H. Brooks , J. Lang

Many astrophysical environments such as X-ray binaries, active galactic nuclei, and accretion disks of compact objects have photoionized plasmas. The strong photoionizing environment found near these bright X-ray sources can be produced in…

Plasma Physics · Physics 2018-12-26 Pawel M. Kozlowski , Roberto C. Mancini , Mark E. Koepke

During non-flaring times, the radio flux of the Sun at the wavelength of a few centimeters to several tens of centimeters mostly originates from the thermal bremsstrahlung emission, very similar to the EUV radiation. Owing to such a…

Solar and Stellar Astrophysics · Physics 2020-03-11 Z. F. Li , S. H. Hua , X. Cheng , M. D. Ding

The Sun's corona has interested researchers for multiple reasons, including the search for solution for the famous coronal heating problem and a purely practical consideration of predicting geomagnetic storms on Earth. There exist numerous…

Solar and Stellar Astrophysics · Physics 2019-11-13 Dan Aksim , Alexey Melnikov , Dmitry Pavlov , Sergey Kurdubov