Related papers: Molecular gas at intermediate redshifts

We describe a new technique to estimate variations in the fundamental constants using 18cm OH absorption lines. This has the advantage that all lines arise in the same species, allowing a clean comparison between the measured redshifts. In…

We report on strong H2 and CO absorption from gas within the host galaxy of gamma-ray burst (GRB) 080607. Analysis of our Keck/LRIS afterglow spectrum reveals a very large HI column density (NHI = 10^22.70 cm^-2) and strong metal-line…

We present the results of HI and OH absorption measurements towards a sample of radio sources using the Arecibo 305-m telescope and the GMRT. In total, 27 radio sources were searched for associated 21-cm HI absorption. One totally new HI…

We perform a systematic study of physical properties and distribution of neutral and ionised gas in the halo of the Milky Way (MW). Beside the large neutral intermediate- and high-velocity cloud (IVC, HVC) complexes there exists a…

We detect the 21 cm line of neutral hydrogen in absorption at a redshift of 0.673 towards the 1 Jy radio source 1504+377. The 1504+377 radio source is located toward the center of what appears to be an inclined disk galaxy at z = 0.674. The…

We have used the Arecibo telescope to carry out an survey of 31 dark clouds in the Taurus/Perseus region for narrow absorption features in HI ($\lambda$ 21cm) and OH (1667 and 1665 MHz) emission. We detected HI narrow self--absorption…

The abundance of H2 in molecular clouds, relative to the commonly used tracer CO, has only been measured toward a few embedded stars, which may be surrounded by atypical gas. We present observations of near-infrared absorption by H2, CO,…

We have analyzed the spectrum of the quasar PKS 1232+082 obtained by Petitjean et al. (2000). HD molecular lines are identified in an absorption system at the redshift z=2.3377. The column density of HD molecules in the system is estimated,…

We present extensive metal-line absorption properties for 45 absorption systems that were selected by their Mg II absorption at redshifts between 0.4 and 1.4. For each system the properties of several chemical species are determined,…

Aims. The comparative study of several molecular species at the origin of the gas phase chemistry in the diffuse interstellar medium (ISM) is a key input in unraveling the coupled chemical and dynamical evolution of the ISM. Methods. The…

We report the detection of absorption by interstellar hydroxyl cations and water cations, along the sight-line to the bright continuum source W49N. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 972 GHz N…

We present a complete catalogue of 27 O VI absorbers at low redshift (0.12 < z < 0.5) from a blind survey of 16 QSO echelle spectra in the HST/STIS data archive. These absorbers are identified based only upon matching line profiles and the…

Using Hubble Space Telescope/Space Telescope Imaging Spectrograph G140M spectroscopy, we investigate an absorption-line system at $z$=0.07489 in the spectrum of the quasi-stellar object PG 1543+489 ($z_{QSO}$=0.401). The sightline passes…

Intervening HI 21-cm absorption systems at z > 1.0 are very rare and only 4 confirmed detections have been reported in the literature. Despite their scarcity, they provide interesting and unique insights into the physical conditions in the…

Absorption-line spectroscopy of multiply-lensed QSOs near a known foreground galaxy provides a unique opportunity to go beyond the traditional one-dimensional application of QSO probes and establish a crude three-dimensional (3D) map of…

This paper analyzes the 53.3um line in the ISO LWS spectra towards a similar sample of OH/IR sources. We find 137 LWS spectra covering 53.3um and associated with 47 galactic OH/IR sources. Ten of these galactic OH/IR sources are found to…

We present a physically-based absorption-line model for the spectroscopic study of the intergalactic medium (IGM). This model adopts results from Cloudy simulations and theoretical calculations by Gnat and Sternberg (2007) to examine the…

We report on a survey for associated HI 21-cm and OH 18-cm absorption with the Giant Metrewave Radio Telescope at redshifts z = 0.2-0.4. Although the low redshift selection ensures that our targets are below the critical ultra-violet…

We present results from MUSE observations of a 21-cm HI absorption system detected with the Australian Square Kilometre Array Pathfinder radio telescope at redshift $z = 0.4503$ towards the $z = 1.71$ quasar PKS 1610-771. We identify four…

Trends observed in galaxies, such as the Gao \& Solomon relation, suggest a linear relation between the star formation rate and the mass of dense gas available for star formation. Validation of such relations requires the establishment of…