Related papers: Variable NaI Absorption toward rho Leo : Biased Ne…

Using the Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope, we have obtained high-resolution ultraviolet spectra of the C I absorption toward two stars behind the Local Leo Cold Cloud (LLCC). At a distance (~20…

We have made HI 21cm-line absorption measurements using the GMRT towards 15 directions in the Galaxy which are known to have high random velocity clouds as seen in the optical absorption lines of CaII and NaI. For the first time, in 6 out…

We present a reanalysis of the HeII Lyman alpha absorption towards the quasars HS1700+6416 and HE2347-4342 using new high S/N, optical observations. An alternative analysis method is applied, which fits the high quality, optical HI data…

We have monitored the massive binary star $\eta$ Carinae with the CTIO/SMARTS 1.5~m telescope and CHIRON spectrograph from the previous apastron passage of the system through the recent 2014.6 periastron passage. Our monitoring has resulted…

Na I D absorbing systems toward Type Ia supernovae (SNe Ia) have been intensively studied over the last decade with the aim of finding circumstellar material (CSM), which is an indirect probe of the progenitor system. However, it is…

We assess the cosmological variability of the fine-structure constant from the analysis of an ensemble of Fe II absorption lines at the redshift z=1.15 toward the QSO HE 0515-4414 by means of the standard many-multiplet (MM) technique and…

Near-infrared observations of line emission from excited H2 and in the continuum are reported in the direction of the Orion molecular cloud OMC1, using the European Southern Observatory Very Large Telescope UT4, equipped with the NAOS…

Unlike the neutral gas density, which remains largely constant over redshifts of 0 < z < 5, the star formation density exhibits a strong redshift dependence, increasing from the present day before peaking at a redshift of z ~ 2.5. Thus,…

We present new interferometer molecular observations of R Leo taken at 1.2 mm with the Atacama Large Millimeter Array with an angular resolution up to ~0.026 arcsec. These observations permit us to resolve the innermost envelope of this…

(abridged) Aims. To reconstruct the spectral shape of the quasar ionizing radiation in the extreme-UV range (1Ryd <= E < 10Ryd) from the analysis of narrow absorption lines (NAL) of the associated systems. Methods. Computational technique…

Using high resolution, high signal-to-noise ultraviolet spectra of the z = 0.9754 quasar PG1148+549 obtained with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, we study the physical conditions and abundances of…

We compare existing high spectral resolution (R=40,000) CaII K observations towards 88 mainly B-type stars, and new observations at R=10,000 towards 3 stars, with 21-cm HI emission-line profiles, in order to search for optical absorption…

We determine the D/H ratio in the interstellar medium toward the DO white dwarf PG0038+199 using spectra from the Far Ultraviolet Spectroscopic Explorer (FUSE), with ground-based support from Keck HIRES. We employ curve of growth, apparent…

We present new imaging and spectroscopic observations of the fields of five QSOs with very strong intervening CaII absorption systems at redshifts z<0.5 selected from the Sloan Digital Sky Survey. Recent studies of these very rare absorbers…

The abundances of ices in planetary environments have historically been obtained through measurements of near-infrared absorption features (lambda = 1.0-2.5 microns), and near-IR transmission measurements of materials present in the…

We present a detailed study of HI and metals for 110 MgII absorption systems discovered at 1.98 <= z <= 5.33 in the infrared spectra of high redshift QSOs. Using new measurements of rest-frame UV lines from optical spectra of the same…

High-dispersion IUE data encode significant information about aggregate line absorptions that cannot be conveniently extracted from individual spectra. We apply a new technique in which fluxes from each echelle order of a short wavelength…

We perform a multiwavelength study toward the SNR G18.1-0.1 and nearby several HII regions (infrared dust bubbles N21 and N22, and the HII regions G018.149-00.283 and G18.197-00.181). Our goal is to provide observational evidence supporting…

FUSE spectra of the white dwarf stars G191-B2B, GD 394, WD 2211-495 and WD 2331-475 cover the absorption features out of the ground electronic states of N I, N II, N III, O I and Ar I in the far ultraviolet, providing new insights on the…

The strongest transitions of Zn and CrII are the most sensitive to relative variations in the fine-structure constant ($\Delta\alpha/\alpha$) among the transitions commonly observed in quasar absorption spectra. They also lie within just…