Related papers: Towards a standardised line list for G191-B2B, and…
We present a catalogue of previously unpublished optical and infrared photometry for a sample of 162 emission-line objects and shell stars visible from the southern hemisphere. The data were obtained between 1978 and 1997 in the Walraven…
For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model-atmospheres are mandatory. These are strongly dependent on the reliability of the…
An atlas of far-ultraviolet spectra of 45 Galactic OB stars observed with the Far Ultraviolet Spectroscopic Explorer is presented. The atlas covers the wavelength region between 912 and 1185A with an effective spectral resolution of 0.12A.…
We studied the spectra of six $z \sim 2.2$ quasars obtained with the X-shooter spectrograph at the Very Large Telescope. The redshift of these sources and X-shooter's spectral coverage allow us to cover the rest spectral range $\sim1200 -…
Diffuse interstellar bands are usually observed in spectra of hot stars, where interstellar lines are rarely blended with stellar ones. The need for hot stars is a strong limitation in the number of sightlines we can observe and the…
We review problems raised by Fe II emission in AGNs and address the question of its relationship to other broad-line region (BLR) lines. The self-shielding, stratified, BLR model of Gaskell, Klimek & Nazarova (2007; GKN) predicts that Fe II…
Low-Ionisation Nuclear Emission-line Regions (LINERs) are the least luminous and the most numerous among the local population of Active Galactic Nuclei (AGN). They can be classified as type-1 or type-2 if their optical spectra show or do…
We describe a moderate-resolution (20-25 km/s) FUSE study of the low-redshift intergalactic medium. We report on studies of 7 extragalactic sightlines and 12 Ly-beta absorbers that correspond to Ly-alpha lines detected by HST/GHRS and STIS.…
The radio complex Sgr B region is observed with the X-Ray Imaging Spectrometers (XIS) on board Suzaku. This region exhibits diffuse iron lines at 6.4, 6.7 and 6.9 keV, which are K$\alpha$ lines of Fe \emissiontype{I} (neutral iron),…
We propose a line list that may be useful for the abundance analysis of G-type stars in the wavelength range 4080 -- 6780 A. It is expected that the line list will be useful for surveys/libraries with overlapping spectral regions (e.g.…
Neutral Fe lines are the most abundant in the spectrum of late stars. They are used to obtain different basic stellar parameters such as relative abundances, surface gravity, and effective temperature. However, the centers of many of these…
This paper presents a theoretical investigation on the polarization and magnetic sensitivity of the near-ultraviolet (near-UV) solar spectral lines of Fe II between 250 and 278 nm. In recent years, UV spectropolarimetry has become key to…
We report the discovery of a further line of sight allowing detection of HeII Ly alpha absorption by the intergalactic medium. A HST/STIS survey of 32 bright z ~ 3 quasars selected from the Hamburg Quasar Surveys yielded one detection…
We present Hubble Space Telescope optical and near-ultraviolet transmission spectra of the transiting hot-Jupiter HD189733b, taken with the repaired Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the…
Iron emission is often a severe contaminant in optical-ultraviolet spectra of active galaxies. Its presence complicates emission line studies. A viable solution, already successfully applied at optical wavelengths, is to use an empirical…
Damped Ly-alpha Systems (DLAs), with N(HI)>2*10^20 cm^{-2}, observed in quasars have allowed us to quantify the chemical content of the Universe over cosmological scales. Such studies can be extended to lower N(HI), in the sub-DLA range…
The properties of the relativistically broadened Fe K alpha line emitted in Active Galactic Nuclei (AGN) are still debated among the AGN community. Recent works seem to exclude that the broad Fe line is a common feature of AGN. The analysis…
We discuss the rest-frame ultraviolet emission line spectra of a large (~100) sample of low luminosity redshift z~3.1 Lyman alpha emitters (LAEs) drawn from a Subaru imaging survey in the SSA22 survey field. Our earlier work based on…
The transmission spectrum of the ultrahot Jupiter KELT-9b ($T_{eq}$ $\sim$ 4000 K) exhibits absorption by several metal species. We searched for atomic and molecular lines in its emission spectrum by observing partial phase curves with the…
With an aim to study whether the close correlation between [Na/H] and [Fe/H] recently found in A-type stars further persists in the regime of B-type stars, the abundances of Na were determined for 30 selected sharp-lined late B-type stars…