相关论文: Solar Flare Chromospheric Line Emission: Compariso…
The hydrogen Lyman-$\alpha$ (H {\sc i} Ly$\alpha$) emission during solar flares has rarely been studied in spatially resolved images and its physical origin has not been fully understood. In this paper, we present novel Ly$\alpha$ images…
The origin of the near-ultraviolet and optical continuum radiation in flares is critical for understanding particle acceleration and impulsive heating in stellar atmospheres. Radiative-hydrodynamic simulations in 1D have shown that high…
The presence of flare related acoustic emission (sunquakes) in some flares represents a severe challenge to our current understanding of flare energy transport processes. We present a comparison of new spectral observations from Hinode's…
Sun-as-a-star analyses serve as a bridge for comparative studies on solar and stellar activities. To investigate the typical Sun-as-a-star Ha temporal spectral characteristics in solar eruption source regions, we analyzed five different…
We report high-resolution observations at mid-infrared wavelengths of a minor solar flare, SOL2014-09-24T17T17:50 (C7.0), using Quantum Well Infrared Photodetector (QWIP) cameras at an auxiliary of the McMath-Pierce telescope. The flare…
I report on the high resolution spectra of the remarkable X9 solar flare of 2024 Oct 03 (SOL2024-10-03T12:08) and evaluate the extent to which nonthermal electron beams that generate dense chromospheric condensations can power very bright…
The sites of chromospheric excitation during solar flares are marked by extended extreme ultraviolet ribbons and hard X-ray footpoints. The standard interpretation is that these are the result of heating and bremsstrahlung emission from…
Analysis of RHESSI 3--10 keV spectra for 27 solar flares is reported. This energy range includes thermal free--free and free--bound continuum and two line features, at 6.7keV and 8keV, principally due to highly ionized iron (Fe). We used…
Solar spectra of ultraviolet bursts and flare ribbons from the Interface Region Imaging Spectrograph (IRIS) have suggested high electron densities of $>10^{12}$ cm$^{-3}$ at transition region temperatures of 0.1 MK, based on large intensity…
Solar flares release an enormous amount of energy into the corona. A substantial fraction of this energy is transported to the lower atmosphere, which results in chromospheric heating. The mechanisms that transport energy to the lower solar…
We compare time variations of the H$\alpha$ and X-ray emissions observed during the pre-impulsive and impulsive phases of the C1.1-class solar flare on 21 June 2013 with those of plasma parameters and synthesized X-ray emission from a…
A popular scenario for electron acceleration in solar flares is transit-time damping of low-frequency MHD waves excited by reconnection and its outflows. The scenario requires several processes in sequence to yield energetic electrons of…
Context. Since the mechanism of energy release from solar flares is still not fully understood, the study of fine-scale features developing during flares becomes important for progressing towards a consistent picture of the essential…
Flares on dM stars contain plasmas at very different temperatures and thus affect a wide wavelength range in the electromagnetic spectrum. While the coronal properties of flares are studied best in X-rays, the chromosphere of the star is…
We report multi-wavelength ultraviolet observations taken with the IRIS satellite, concerning the emergence phase in the upper chromosphere and transition region of an emerging flux region (EFR) embedded in the pre-existing field of active…
We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph (IRIS). The observations were made of a solar active region on 2015 December 18 as part of the…
The Interface Region Imaging Spectrograph (IRIS) has been obtaining near- and far-ultraviolet images and spectra of the solar atmosphere since July 2013. The unique combination of near and far-ultraviolet spectra and images at subarcsecond…
We present direct evidence for the detection of the main energy release site in a non-eruptive solar flare, SOL2013-11-09T06:38UT. This GOES C2.7 event was characterised by two flaring ribbons and a compact, bright coronal source located…
Aims: This paper aims to demonstrate the importance of short-exposure extreme ultraviolet (EUV) observations of solar flares in the study of particle acceleration, heating and energy partition in flares. This work highlights the…
Context: On 2022 May 4, an M5.7 flare erupted in the active region NOAA 13004, which was the target of a coordinated campaign between GREGOR, IRIS, Hinode, and ground-based instruments at the Ond\v{r}ejov observatory. A flare kernel located…