相关论文: Highly ionized Calcium and Argon X-ray spectra fro…
The {\em DIOGENESS} X-ray crystal spectrometer on the {\em CORONAS-F} spacecraft operated for a single month (25~August to 17~September) in 2001 but in its short lifetime obtained one hundred and forty high-resolution spectra from some…
Archived high-resolution X-ray spectra in the 13~\AA\ to 22~\AA\ range from the Flat Crystal Spectrometer (FCS), an instrument on the Solar Maximum Mission operating in the 1980s, are analyzed with reference to nonflaring active regions,…
It is shown that the dielectronic satellites (DES) dominate X-ray spectral formation in the 6.7 keV K-alpha complex of Fe XXV at temperatures below that of maximum abundance in collisional ionization equilibrium T_m. Owing to their extreme…
The abundance of potassium is derived from X-ray lines observed during flares by the RESIK instrument on the solar mission CORONAS-F between 3.53 A and 3.57 A. The lines include those emitted by He-like K and Li-like K dielectronic…
We report on calcium abundance $A({\rm Ca})$ estimates during the decay phases of 194 solar X-ray flares using archived data from the Bent Crystal Spectrometer (BCS) on Solar Maximum Mission (operational 1980~--~1989). The abundances are…
The Ar XVII X-ray line group principally due to transitions 1s2 - 1s2l (l=s, p) near 4 Anstroms was observed in numerous flares by the RESIK bent crystal spectrometer aboard CORONAS-F between 2001 and 2003. The three line features include…
X-ray spectra in the range $1.5-8.5$~keV have been analyzed for 526 large flares detected with the Solar Assembly for X-rays (SAX) on the Mercury {\em MESSENGER} spacecraft between 2007 and 2013. For each flare, the temperature and emission…
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…
{The \ion{Na}{x} X-ray lines between 10.9 and 11.2~\AA\ have attracted little attention but are of interest since they enable an estimate of the coronal abundance of Na to be made. This is of great interest in the continuing debate on the…
We have reviewed the first year of observations of the Solar X-ray Monitor (XSM) onboard Chandrayaan-2, and the available multi-wavelength observations to complement the XSM data, focusing on Solar Dynamics Observatory AIA and Hinode XRT,…
Spectroscopic observations in X-ray wavelengths provide excellent diagnostics of the temperature distribution in solar flare plasma. The Solar X-ray Monitor (XSM) onboard the Chandrayaan-2 mission provides broad-band disk integrated soft…
Solar flares involve impulsive energy release, which results in enhanced radiation over a broad spectral range and a wide range of heights. In particular, line emission from the chromosphere can provide critical diagnostics of plasma…
The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in {\em RHESSI} X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an…
The calcium abundance in flare plasmas is estimated using X-ray spectra from the Solar Maximum Mission Bent Crystal Spectrometer (BCS) during the decays of 194 flares (GOES classifications from B6.4 to X13) occurring between 1980 and 1989.…
Chandra HETG spectra of the coronally active binary stars sigma Gem and HR 1099 are among the highest fluence observations for such systems taken at high spectral resolution in x-rays with this instrument. We compare their properties to…
This paper describes the development of X-ray diffractive optics for imaging solar flares with better than 0.1 arcsec angular resolution. X-ray images with this resolution of the \geq10 MK plasma in solar active regions and solar flares…
The abundance of chlorine is determined from X-ray spectra obtained with the RESIK instrument on {\em CORONAS-F} during solar flares between 2002 and 2003. Using weak lines of He-like Cl, \ion{Cl}{16}, between 4.44 and 4.50 \AA, and with…
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…
The X-ray Imaging and Spectroscopy Mission (XRISM), launched into low-Earth orbit in 2023, observes the reflection of solar flare X-rays in the Earth's atmosphere as a by-product of celestial observations. Using a $\sim$one-year data set…
A high-resolution X-ray spectroscopic observation was made of the RS CVn-type binary star HR 1099 using the Resolve instrument onboard XRISM for its calibration purposes. During the $\sim$400 ks telescope time covering 1.5 binary orbit, a…