Related papers: Velocity Characteristics of Evaporated Plasma Usin…
Here we present the study of a compact emission source during an X1.3 flare on 2022-March-30. Within a $\sim41$~s period (17:34:48 UT to 17:35:29 UT), IRIS observations show spectral lines of Mg II, C II and Si IV with extremely broadened,…
We investigate the relationship between the blue shifts of a hot emission line and the nonthermal emissions in microwave and hard X-ray (HXR) wavelengths during the precursor of a solar flare on 2014 October 27. The flare precursor is…
Low-amplitude Doppler-shift oscillations have been observed in coronal emission lines in a number of active regions with the EUV Imaging Spectrometer (EIS) on the Hinode satellite. Both standing and propagating waves have been detected and…
Differential emission measures (DEMs) during the impulsive phase of solar flares were constructed using observations from the EUV Variability Experiment (EVE) and the Markov-Chain Monte Carlo method. Emission lines from ions formed over the…
In this paper, we analyze the high-resolution UV spectra for a C1.7 solar flare (SOL2017-09-09T06:51) observed by the \textit{Interface Region Imaging Spectrograph} (\textit{IRIS}). {We focus on the spectroscopic observations at the…
In previous studies a very hot plasma component has been diagnosed in solar active regions through the images in three different narrow-band channels of SDO/AIA. This diagnostic from EUV imaging data has also been supported by the matching…
We study the chromospheric LOS velocities during the GOES M3.2 flare (SOL2013-05-17T08:43) using simultaneous spectroscopic data of the He I 1083.0 nm triplet and Ca II 854.2 nm line. A filament was present in the flaring area. The…
We studied an X1.6 solar flare produced by NOAA AR 12602 on 2014 October 22. The entirety of this event was covered by RHESSI, IRIS, and Hinode/EIS, allowing analysis of the chromospheric response to a nonthermal electron driver. We derived…
Non-thermal velocities, derived from spectral line broadening, can provide crucial insights into plasma dynamics before and during solar flares. To systematically study the pre-flare phase, we constructed a Hinode/Extreme-ultraviolet…
A detailed study of emission lines from Fe VII, Fe VIII and Fe IX observed by the EUV Imaging Spectrometer on board the Hinode satellite is presented. Spectra in the ranges 170-212 A and 246-292 A show strongly enhanced lines from the upper…
Four Fe IX transitions in the wavelength range 188--198 A are identified for the first time in spectra from the EUV Imaging Spectrometer on board the Hinode satellite. In particular the emission line at 197.86 A is unblended and close to…
The properties of solar flare plasma can be determined from the observation of optically thin lines. The emitting ion distribution determines the shape of the line, with an isothermal Maxwellian ion distribution producing a Gaussian…
We present observations of SS 433 using the Chandra High Energy Transmission Grating Spectrometer. Many emission lines of highly ionized elements are detected with the relativistic blue and red Doppler shifts. The lines are measurably…
Using the observations recorded by Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO), the Interface Region Imaging Spectrograph (IRIS) and the Extreme-ultraviolet Imaging Spectrometer (EIS) and X-Ray Telescope…
Monitor of All-sky X-ray Image (MAXI) detected a superflare, releasing $5\times 10^{37}$ erg in 2$-$10 keV, of the RS CVn-type star IM Peg at 10:41 UT on 2023 July 23 with its Gas Slit Camera (GSC; 2$-$30 keV). We conducted X-ray follow-up…
Using one-arcsecond-slit scan observations from the Hinode/EUV Imaging Spectrometer (EIS) on 05 February 2007, we find the plasma outflows in the open and expanding coronal funnels at the eastern boundary of AR 10940. The Doppler velocity…
The Extreme ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft has been operating since 2006, returning high resolution data in the 170-212 and 246-292 A wavelength regions. EIS has four slit options, with the narrow 1"…
Context: Long-period intensity pulsations were recently detected in the EUV emission of coronal loops, and have been attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations…
Observations of extreme-ultraviolet (EUV) emission from an X-class solar flare that occurred on 2011 February 15 at 01:44 UT are presented, obtained using the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory. The…
We report on observations of a solar prominence obtained on 26 April 2007 using the Extreme Ultraviolet Imaging Spectrometer on Hinode. Several regions within the prominence are identified for further analysis. Selected profiles for lines…