English
Related papers

Related papers: Solar UV and X-Ray Spectral Diagnostics

200 papers

M dwarf stars are excellent candidates around which to search for exoplanets, including temperate, Earth-sized planets. To evaluate the photochemistry of the planetary atmosphere, it is essential to characterize the UV spectral energy…

Solar flare electron acceleration is an efficient process, but its properties (mechanism, location) are not well constrained. Via hard X-ray (HXR) emission, we routinely observe energetic electrons at the Sun, and sometimes we detect…

Solar and Stellar Astrophysics · Physics 2023-10-09 Ross Pallister , Natasha L. S. Jeffrey

Surges are cool and dense ejections typically observed in chromospheric lines and closely related to other solar phenomena like UV bursts or coronal jets. Our aim is to address the current lack of inverted models and diagnostics of surges…

Solar and Stellar Astrophysics · Physics 2021-11-10 D. Nóbrega Siverio , S. L. Guglielmino , A. Sainz Dalda

We analyze a pair of Suzaku shadowing observations in order to determine the X-ray spectrum of the Galaxy's gaseous halo. We simultaneously fit the spectra with models having halo, local, and extragalactic components. The intrinsic…

Astrophysics of Galaxies · Physics 2009-07-24 Shijun Lei , Robin L. Shelton , David B. Henley

The calculations of the ratios of the Helium-like ion X-ray lines from C V to Si XIII are revisited in order to apply the results to density, temperature and ionization process diagnostics of data from high-resolution spectroscopy of the…

Astrophysics · Physics 2007-05-23 D. Porquet , R. Mewe , J. S. Kaastra , J. Dubau , A. J. J. Raassen

Transient X-ray absorption techniques can measure ultrafast dynamics of the elemental edges in a material or multiple layer junction, giving them immense potential for deconvoluting concurrent processes. However, the interpretation of the…

Materials Science · Physics 2021-06-10 Hanzhe Liu , Isabel M. Klein , Jonathan M. Michelsen , Scott K. Cushing

Information about the physical properties of astrophysical objects cannot be measured directly but is inferred by interpreting spectroscopic observations in the context of atomic physics calculations. Ratios of emission lines, for example,…

The Spectrometer/Telescope for Imaging X-rays (STIX) is one of the 10 instruments on-board the scientific payload of ESA's Solar Orbiter mission. STIX provides hard X-ray imaging spectroscopy in the 4-150~keV energy range, observing hard…

Solar and Stellar Astrophysics · Physics 2023-04-05 Laura A. Hayes , Sophie Musset , Daniel M üller , S äm Krucker

Previous estimates of the solar flare abundances of Si, S, Cl, Ar, and K from the RESIK X-ray crystal spectrometer on board the CORONAS-F spacecraft were made on the assumption of isothermal X-ray emission. We investigate the effect on…

Solar and Stellar Astrophysics · Physics 2015-06-19 B. Sylwester , J. Sylwester , K. J. H. Phillips , A. Kepa , T. Mrosek

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

For the last decade numerous researchers have been trying to develop experimental techniques to use X-ray Thomson scattering as a method to measure the temperature, electron density, and ionization state of high energy density plasmas such…

Plasma Physics · Physics 2012-10-02 J. Nilsen , W. R. Johnson , K. T. Cheng

Hard X-ray (HXR) spectroscopy is the most direct method of diagnosing energetic electrons in solar flares. Here we present a technique which allows us to use a single HXR spectrum to determine an effectively stereoscopic electron energy…

Astrophysics · Physics 2009-11-11 Eduard P. Kontar , John C. Brown

We review the terms, spectral radiance and spectral irradiance, and show how their precise definitions are crucial for interpreting observations made with different instruments covering widely different energy or wavelength ranges. We show…

Solar and Stellar Astrophysics · Physics 2024-03-25 Brian R. Dennis , Kenneth J. H. Phillips

In addition to X-rays, extreme ultraviolet (EUV) rays radiated from solar flares can cause serious problems, such as communication failures and satellite drag. Therefore, methods for forecasting EUV dynamic spectra during flares are…

Solar and Stellar Astrophysics · Physics 2020-05-14 Toshiki Kawai , Shinsuke Imada , Shohei Nishimoto , Kyoko Watanabe , Tomoko Kawate

The most popular method for determining coronal temperatures is the scale-height-method (shm). It is based on electron density profiles inferred from White Light (WL) brightness measurements of the corona during solar eclipses. This method…

Solar and Stellar Astrophysics · Physics 2012-01-19 J. F. Lemaire

Energetic disorder has been known for decades to limit the performance of structurally disordered semiconductors such as amorphous silicon and organic semiconductors. However, in the past years, high performance organic solar cells have…

Small-scale transient phenomena in the quiet Sun are believed to play an important role in coronal heating and solar wind generation. One of them named as "X-ray jet" is the subject of our study. We indent to investigate the dynamics,…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. S. Madjarska

Magnetic fields are the primary driver of the plasma thermodynamics in the upper solar atmosphere, especially in the corona. However, magnetic field measurements in the solar corona are sporadic, thereby limiting us from the complete…

Solar and Stellar Astrophysics · Physics 2024-06-12 Raveena Khan , Sarah E. Gibson , Roberto Casini , K. Nagaraju

The ultraviolet (UV) window has been largely unexplored through balloons for astronomy. We discuss here the development of a compact near-UV spectrograph with fiber optics input for balloon ights. It is a modified Czerny-Turner system built…

Instrumentation and Methods for Astrophysics · Physics 2016-10-03 A. G. Sreejith , Joice Mathew , Mayuresh Sarpotdar , K. Nirmal , S. Ambily , Ajin Prakash , Margarita Safonova , Jayant Murthy

We propose a collective Thomson scattering experiment at the VUV free electron laser facility at DESY (FLASH) which aims to diagnose warm dense matter at near-solid density. The plasma region of interest marks the transition from an ideal…

Plasma Physics · Physics 2015-06-26 A. Hoell
‹ Prev 1 4 5 6 7 8 10 Next ›