Related papers: New EUV Fe IX emission line identifications from H…
We present Maxwellian-averaged effective collision strengths for the electron-impact excitation of S III over a wide range of electron temperatures of astrophysical importance, log T(K) = 3.0-6.0. The calculation incorporates 53…
High-resolution Doppler-resolved spectroscopy has opened up a new window into the atmospheres of both transiting and non-transiting exoplanets. Here, we present VLT/UVES observations of a transit of WASP-121b, an 'ultra-hot' Jupiter…
Recent fully relativistic calculations of radiative rates and electron impact excitation cross sections for Fe {\sc xiii} are used to generate emission-line ratios involving 3s$^{2}$3p$^{2}$--3s3p$^{3}$ and 3s$^{2}$3p$^{2}$--3s$^{2}$3p3d…
In the work described here we investigate atomic processes leading to the formation of emission lines within the IRIS wavelength range at temperatures near $10^5$~K. We focus on (1) non-equilibrium and (2) density-dependent effects…
We discuss observations of chromospheric evaporation for a complex flare that occurred on 9 March 2012 near 03:30 UT obtained from the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. This was a multiple event with a…
DEM analysis is a major diagnostic tool for stellar atmospheres. But both its derivation and its interpretation are notably difficult because of random and systematic errors, and the inverse nature of the problem. We use simulations with…
We use UV spectral observations of active regions with the Interface Region Imaging Spectrograph (IRIS) to investigate the properties of the coronal FeXII 1349.4A emission at unprecedented high spatial resolution (~0.33"). We find that by…
On January 14, 2001, shortly after the Cassini spacecraft's closest approach to Jupiter, the Ultraviolet Imaging Spectrometer (UVIS) made a radial scan through the midnight sector of Io plasma torus. The Io torus has not been previously…
We present an update to the in-flight radiometric calibration of the Hinode EUV Imaging Spectrometer (EIS), revising and extending our previous studies. We analyze full-spectral EIS observations of quiet Sun and active regions from 2007…
We present a study of spectral line width measurements from the Extreme Ultraviolet Imaging Spectrometer (EIS) on {\it Hinode}. We used spectral line profiles of Fe {\sc xvi} 262.984 {\AA}, Fe {\sc xiv} 264.787 {\AA}, Fe {\sc xiv} 270.519…
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…
We present a study of the properties of the transition temperature (T~10^5 K) gas in the Milky Way corona, based on measurements of OVI, NV, CIV, SiIV and FeIII absorption lines seen in the far ultraviolet spectra of 58 sightlines to…
We present analyses of observations of epsilon Eridani (K2 V) made with the Low Energy Transmission Grating Spectrometer on Chandra and the Extreme Ultraviolet Explorer, supplemented by observations made with the Space Telescope Imaging…
We have used an electron beam ion trap to measure electron-density-diagnostic line-intensity ratios for extreme ultraviolet lines from F XII, XIII, and XIV at wavelengths of 185-205 255-276 Angstroms. These ratios can be used as density…
The temperatures of the heavy ions ($T_i$) in the solar corona provide critical information about the heating mechanism of the million-degree corona. However, the measurement of $T_i$ is usually challenging due to the nonthermal motion,…
The isotope shift between singly-charged ^<151>Eu and ^<153>Eu in the 4f^7(^8S^o)6s^9S_4-4f^7(^8S^o)6p_1/2>(J=4) transition at 4129 A has been measured using fast ion beam-laser technique. This Eu line has attracted interest in connection…
We present spectroscopic observations of ionized gas in the disk-halo regions of five edge-on galaxies, covering a wavelength range from [OII] 3727A to [SII] 6716.4A. The inclusion of the [OII] emission provides additional constraints on…
The EUV Imaging Spectrometer (EIS) on the Hinode satellite is capable of measuring emission line center positions for Gaussian line profiles to a fraction of a spectral pixel, resulting in relative solar Doppler-shift measurements with an…
This paper investigates a quiescent (non-flaring) active region observed on July 13, 2010 in EUV, SXR, and HXRs to search for a hot component that is speculated to be a key signature of coronal heating. We use a combination of RHESSI…
The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode is the first solar telescope to obtain wide slit spectral images that can be used for detecting Doppler flows in transition region and coronal lines on the Sun and to relate…