Results 71 to 80 of about 859 (172)

Power-law Indices of EUV Intensity Power Spectrum in Flaring Coronal Active Regions

The Astrophysical Journal
Solar intensity power spectra are usually characterized by colored noise, with the spectral energy following a segmented power-law function of frequency, S ( f ) ∝ f ^− ^α , over different frequency ranges. Typically, the power-law index exceeds 1 in the
Sihui Zhong, Dmitrii Y. Kolotkov, Valery M. Nakariakov   +2 more
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Radio, X-ray, and extreme ultraviolet signatures of internal and external reconnection of an erupting flux rope

Astronomy & Astrophysics
Aims. We aim to interpret and relate features observed in gigahertz radio, extreme UV (EUV), and X-ray emissions during a filament eruption at the start of a solar flare on 2 April 2022. Methods.
Kašparová Jana, Dudík Jaroslav, Karlický Marian, Zemanová Alena, Massa Paolo, Krucker Samuel, Schuller Frédéric, Rybák Ján   +7 more
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X-Ray and EUV Spectra of Solar Flares and Laboratory Plasmas [PDF]

Symposium - International Astronomical Union, 1975
Recent laboratory work relevant to solar flares on the spectroscopy of highly ionized atoms is reviewed. Much of this work has concerned the X-ray and EUV spectrum of iron ions, Fe XVIII–Fe XXIV, which produce prominent emission lines in the spectra of solar flares.
openaire   +1 more source

NE V line ratios in the EUV spectra of solar flares

The Astrophysical Journal, 1992
Theoretical line ratios involving 2s(2)2p(2)-2s2p3 transitions in Ne v between 359 and 572 angstrom are presented. A comparison of these with solar flare observational data from the Naval Research Laboratory's S082A spectrograph on board Skylab reveals excellent agreement between theory and experiment, with discrepancies that average only 8%.
F. P. Keenan, E. S. Conlon, L. K. Harra, K. M. Aggarwal, K. G. Widing   +4 more
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Time-resolved X-ray spectra of Proxima Centauri as seen by XMM-Newton

Astronomy & Astrophysics
Context. Stellar soft X-ray ([1, 100] Å) and extreme ultraviolet (also EUV, [100, 920] Å; jointly, XUV) radiation affect the evolution and chemistry of exoplanet atmospheres. It is, however, uncertain to what extent the radiation’s short-term variability
Damonte A., Pillitteri I., Maggio A., García Muñoz A., Micela G.   +4 more
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Temporal and spectral variations of the photoelectron flux and solar irradiance during an X class solar flare

Geophysical Research Letters, 2008
Photoelectrons are the main energy source of airglow used to diagnose the state of the ionosphere‐thermosphere system. Because of measurement uncertainties and substantial gaps in the historical record, parameterized models of the EUV irradiance and ...
W. K. Peterson, P. C. Chamberlin, T. N. Woods, P. G. Richards   +3 more
doaj   +1 more source

Empirical Prediction of Plasma Emission Measure Distributions and X-Ray/Extreme-ultraviolet Spectra of Late-type Stars

The Astrophysical Journal
High-energy emission spectra from the outer atmospheres of late-type stars represent an important feature of the stellar activity in several contexts, such as the photoevaporation and photochemistry of planetary atmospheres or the modeling of irradiated ...
A. Maggio, I. Pillitteri, J. Sanz-Forcada, G. Micela   +3 more
doaj   +1 more source

3D Nonequilibrium Ionization and Spectroscopic Modeling of Coronal Mass Ejections. I. Comparison with Hinode/EIS Observations

The Astrophysical Journal
High-resolution EUV spectroscopy provides an informative diagnostic tool for the early evolution of coronal mass ejections (CMEs) since it can directly measure many physical properties of CME plasma close to the Sun that cannot be determined from white ...
E. M. Wraback, E. Landi, W. B. Manchester, J. Szente   +3 more
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Spectral Imager of the Solar Atmosphere: The First Extreme-Ultraviolet Solar Integral Field Spectrograph Using Slicers

Aerospace
Particle acceleration, and the thermalisation of energetic particles, are fundamental processes across the universe. Whilst the Sun is an excellent object to study this phenomenon, since it is the most energetic particle accelerator in the Solar System ...
Ariadna Calcines Rosario, Frederic Auchère, Alain Jody Corso, Giulio Del Zanna, Jaroslav Dudík, Samuel Gissot, Laura A. Hayes, Graham S. Kerr, Christian Kintziger, Sarah A. Matthews, Sophie Musset, David Orozco Suárez, Vanessa Polito, Hamish A. S. Reid, Daniel F. Ryan   +14 more
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Extreme ultraviolet spectral image processing system based on FPGA

He jishu
BackgroundDuring the data acquisition of an extreme ultraviolet (EUV) spectroscopic diagnostic system in experimental advanced superconducting Tokamak (EAST), significant amounts of one-pixel noises are consistently observed.
SUN Bo, LIU Chong, ZHANG Hongming, LYU Bo, YIN Xianghui, LIN Zichao, SHEN Yongcai, JI Huajian, FU Jia, WANG Fudi, HU Kui, FAN Yu, MAO Liyu, ZENG Chao   +13 more
doaj   +1 more source