335 citations · 8.1k across the 221 of their papers we have counts for
11 papers · 2 filters
Implications of an updated ultraviolet background for the ionization mechanisms of intervening Ne VIII absorbers
Tanvir Hussain, Vikram Khaire, Raghunathan Srianand +2
Ne VIII absorbers seen in QSO spectra are useful tracers of warm ionized gas, when collisional ionization is the dominant ionization process. While photoionization by the ultraviol…
Incidence of HI 21-cm absorption in strong FeII systems at
R. Dutta, R. Srianand, N. Gupta +5
We present the results from our search for HI 21-cm absorption in a sample of 16 strong FeII systems ((MgII ) Å and (FeII )…
A ghostly damped Ly system revealed by metal absorption lines
Hassan Fathivavsari, Patrick Petitjean, Siwei Zou +4
We report the discovery of the first 'ghostly' damped Ly absorption system (DLA), which is identified by the presence of absorption from strong low-ion species at $z_{\rm abs}=1…
The Ly emission from high- galaxies hosting strong Damped Ly systems
Ravi Joshi, Raghunathan Srianand, Pasquier Noterdaeme +1
We study the average Ly emission associated with high- strong (log (H I) 21) damped Ly systems (DLAs). We report Ly luminosities () for the full a…
HI 21-cm absorption survey of quasar-galaxy pairs: Distribution of cold gas around z<0.4 galaxies
R. Dutta, R. Srianand, N. Gupta +4
We present the results from our survey of HI 21-cm absorption, using GMRT, VLA and WSRT, in a sample of 55 z<0.4 galaxies towards radio sources with impact parameters (b) in the ra…
Discovery of a Perseus-like cloud in the early Universe: HI-to-H2 transition, carbon monoxide and small dust grains at zabs=2.53 towards the quasar J0000+0048
P. Noterdaeme, J. -K. Krogager, S. Balashev +10
We present the discovery of a molecular cloud at zabs=2.5255 along the line of sight to the quasar J0000+0048. We perform a detailed analysis of the absorption lines from ionic, ne…
Dust-depletion sequences in damped Lyman-α absorbers: a unified picture from low-metallicity systems to the Galaxy
Annalisa De Cia, Cédric Ledoux, Lars Mattsson +4
We study metal depletion due to dust in the interstellar medium (ISM) to infer the properties of dust grains and characterize the metal and dust content of galaxies, down to low me…
Extended Ly emission around quasars with eclipsing damped Ly systems
Hassan Fathivavsari, Patrick Petitjean, Pasquier Noterdaeme +4
We present spectroscopic observations of six high redshift ( 2) quasars, which have been selected for their Lyman (Ly) emission region being only partially c…
Detection of emission lines from z ~ 3 DLAs towards the QSO J2358+0149
Raghunathan Srianand, Tanvir Hussain, Pasquier Noterdaeme +5
Using VLT/X-shooter we searched for emission line galaxies associated to four damped Lyman- systems (DLAs) and one sub-DLA at 2.73<=z<=3.25 towards QSO J2358+0149. We detect [O…
Physical conditions in three high-z H2-bearing DLAs: implications for grain size
Katherine Rawlins, Gargi Shaw, Raghunathan Srianand
We present results of our numerical simulation of three H2-bearing damped Lyman alpha absorbers (DLAs) in the redshift interval ~ 2-3. The systems we have modelled are the DLAs at…
Mapping kiloparsec-scale structures in the extended HI disc of the galaxy UGC 00439 by HI 21-cm absorption
Rajeshwari Dutta, Neeraj Gupta, Raghunathan Srianand +1
We study the properties of HI gas in the outer regions (~2r_25) of a spiral galaxy, UGC 00439 (z = 0.01769), using HI 21-cm absorption towards different components of an extended b…