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相关论文: Lyman-alpha Variability During Solar Flares Over S…

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We extend a previous statistical solar flare study of 155 GOES M- and X-class flares observed with AIA/SDO (Aschwanden 2012) to all 7 coronal wavelengths (94, 131, 171, 193, 211, 304, 335 \ang) to test the wavelength-dependence of scaling…

太阳与恒星天体物理 · 物理学 2015-06-17 Markus J. Aschwanden , Jie Zhang , Kai Liu

Between 2017 and 2024, the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory has observed numerous white-light solar flares (WLFs). HMI spectro-polarimetric observations of certain WLFs, in particular the X9.3…

太阳与恒星天体物理 · 物理学 2025-07-02 Samuel Granovsky , Alexander G. Kosovichev , Viacheslav M. Sadykov , Graham S. Kerr , Joel C. Allred

The solar radiation in the Lyman-alpha spectral line of hydrogen plays a significant role in the illumination of chromospheric and coronal structures, such as prominences, spicules, chromospheric fibrils, cores of coronal mass ejections,…

太阳与恒星天体物理 · 物理学 2020-12-16 S. Gunar , P. Schwartz , J. Koza , P. Heinzel

In this study we measure physical parameters of the same set of 155 M and X-class solar flares observed with AIA/SDO as analyzed in Paper I, by performing a {\sl differential emission measure (DEM)} analysis to determine the flare peak…

太阳与恒星天体物理 · 物理学 2015-06-17 Markus J. Aschwanden , Toshifumi Shimizu

Sympathetic solar flares are eruptions that occur nearby in space and time, driven by an apparent interaction between the active regions in which they are triggered. Their statistical existence on the Sun has yet to be firmly established.…

太阳与恒星天体物理 · 物理学 2025-02-05 Louis-Simon Guité , Antoine Strugarek , Paul Charbonneau

A solar flare is composed of impulsive energy release events by magnetic reconnection, which forms and heats flare loops. Recent studies have revealed a two-phase evolution pattern of UV 1600\AA\ emission at the feet of these loops: a rapid…

太阳与恒星天体物理 · 物理学 2013-09-16 Jiong Qiu , Zoe Sturrock , Dana W. Longcope , James A. Klimchuk , Wen-Juan , Liu

The extreme ultraviolet (EUV) and X-ray radiation emitted during solar flares has been shown to significantly increase the electron density of the Earth's ionosphere. During flares, quasi-periodic pulsations (QPPs) in X-ray flux originating…

太阳与恒星天体物理 · 物理学 2025-04-11 Aisling N. O'Hare , Susanna Bekker , Laura A. Hayes , Ryan O. Milligan

Recent observations of interplanetary medium (IPM) atomic hydrogen Lyman-{\alpha} (Ly{\alpha}) emission in the outer solar system, made with the Alice ultraviolet spectrograph on New Horizons (NH), are presented. The observations include…

We present spectroscopic properties of 22 Lyman-alpha emitters(LAEs) at z=5.5-6.6 with Lyman-alpha(Lya) luminosity log($L_{Lya}$[$ergs^{-1}$])=42.4-43.5, obtained using VLT/MUSE as part of the Middle Ages Galaxy Properties with Integral…

Spatially extended halos of H I Ly$\alpha$ emission are now ubiquitously found around high-redshift star-forming galaxies. But our understanding of the nature and powering mechanisms of these halos is still hampered by the complex radiative…

There is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this enigmatic region…

We have calculated FeII emission line strengths for Active Galactic Nuclei Broad-Line Regions using precise radiative transfer and Iron Project atomic data. We improve the treatment of all previously considered excitation mechanisms for the…

天体物理学 · 物理学 2009-10-30 T. A. A. Sigut , Anil K. Pradhan

We report the discovery of Lyman-alpha emission (Ly$\alpha$) in the bright galaxy EGSY-2008532660 (hereafter EGSY8p7) using the MOSFIRE spectrograph at the Keck Observatory. First reported by Roberts-Borsani et al. (2015), it was selected…

We report on the detection of the gamma-ray emission above 100 MeV from the solar flare of September 29, 2022, by Fermi LAT with simultaneous coverage in HXR by Solar Orbiter STIX. The Solar Orbiter-Earth separation was 178$^{\circ}$ at the…

The chromospheric H-alpha spectral line is a strong line in the spectrum of the Sun and other stars. In the stellar regime, this spectral line is already used as a powerful tracer of stellar activity. For the Sun, other tracers (i.e, CaII…

太阳与恒星天体物理 · 物理学 2022-05-18 A. Diercke , C. Kuckein , P. W. Cauley , K. Poppenhäger , J. D. Alvarado-Gómez , E. Dineva , C. Denker

Identifying the physical mechanisms of continuum emission in solar flares is important to improve our understanding of the transport of energy in the chromosphere. This study aims to quantify the occurrence statistics and spatial and…

太阳与恒星天体物理 · 物理学 2026-04-14 Pranjali Sharma , Lucia Kleint , Jonas Zbinden

We present a multi-instrument study of the two precursor brightenings prior to the M6.5 flare (SOL2015-06-22T18:23) in the NOAA Active Region 12371, with a focus on the temperature (T), electron number density (n), and emission measure…

太阳与恒星天体物理 · 物理学 2023-02-15 Nian Liu , Ju Jing , Yan Xu , Haimin Wang

The RESIK instrument on the CORONAS-F spacecraft obtained solar flare and active region X-ray spectra in four channels covering the wavelength range 3.8 -- 6.1 \AA in its operational period between 2001 and 2003. Several highly ionized…

太阳与恒星天体物理 · 物理学 2015-06-12 B. Sylwester , K. J. H. Phillips , J. Sylwester , A. Kepa

Several mechanisms have been proposed to explain the transient seis- mic emission, i.e., sunquakes, from some solar flares. Some theories associate high-energy electrons and/or white-light emission with sunquakes. High-energy charged…

太阳与恒星天体物理 · 物理学 2015-12-09 J. C. Buitrago-Casas , J. C. Martinez Oliveros , C. Lindsey , B. Calvo-Mozo , S. Krucker , L. Glesener , S. Zharkov

During the epoch of reionization, Ly-alpha photons emitted by the first stars can couple the neutral hydrogen spin temperature to the kinetic gas temperature, providing the opportunity to observe the gas in emission or absorption in the…

天体物理学 · 物理学 2009-11-13 B. Semelin , F. Combes , S. Baek