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Related papers: HI Absorption in GPS/CSS Sources

200 papers

The cross-section of sky occupied by a particular neutral hydrogen column density provides insight into the nature of Lyman-alpha absorption systems. We have measured this column density distribution at z=0 using 21-cm HI emission from a…

Astrophysics · Physics 2007-05-23 Emma Ryan-Weber , Rachel Webster , Lister Staveley-Smith

Galaxy disks are shown to contain a significant population of atomic clouds of 100pc linear size which are self-opaque in the 21cm transition. These objects have HI column densities as high as 10^23 and contribute to a global opacity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Robert Braun

We present results from a search for 21 cm associated HI absorption in a sample of 29 radio sources selected from the Australia Telescope 20 GHz survey. Observations were conducted using the Australia Telescope Compact Array Broadband…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 J. R. Allison , S. J. Curran , B. H. C. Emonts , K. Gareb , E. K. Mahony , S. Reeves , E. M. Sadler , A. Tanna , M. T. Whiting , M. A. Zwaan

The presence, distribution and kinematics of atomic neutral hydrogen in the central regions of galaxies can be traced by the HI 21~cm line observed in absorption. Depending only on the strength of the radio continuum, the associated…

Astrophysics of Galaxies · Physics 2024-12-11 Raffaella Morganti

Different physical processes in galaxy evolution, such as galaxy mergers that lead to coalescence of dual Active Galactic Nuclei (AGN) and outflows emanating from the narrow line region, can leave their imprint on the optical spectra of AGN…

Astrophysics of Galaxies · Physics 2022-09-08 Rajeshwari Dutta , Raghunathan Srianand

In this work, observational evidence for the connection between low column density Lyman-alpha absorbers and large-scale structure traced by gas-rich galaxies is investigated. The HI Parkes All Sky Survey (HIPASS) galaxy catalogue is…

Astrophysics · Physics 2009-11-11 Emma V. Ryan-Weber

From a survey for redshifted HI 21-cm and OH 18-cm absorption in the hosts of a sample of radio galaxies and quasars, we detect HI in three of the ten and OH in none of the fourteen sources for which useful data were obtained. As expected…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 S. J. Curran , M. T. Whiting , M. T. Murphy , J. K. Webb , C. Bignell , A. G. Polatidis , T. Wiklind , P. Francis , G. Langston

We present 1.4 GHz HI absorption line observations towards the starburst in NGC2146, made with the VLA and MERLIN. The HI gas has a rotating disk/ring structure with column densities between 6 and 18 x 10(21) atoms cm(-2). The HI absorption…

Astrophysics · Physics 2007-05-23 A. Tarchi , A. Greve , A. B. Peck , N. Neininger , K. A. Wills , A. Pedlar , U. Klein

We discuss the morphology and kinematics of the HI of a sample of 30 southern gas-rich early-type galaxies selected from the HI Parkes All-Sky Survey (HIPASS). This is the largest collection of high-resolution HI data of a homogeneously…

Astrophysics · Physics 2009-11-13 T. Oosterloo , R. Morganti , E. M. Sadler , J. M. van der Hulst , P. Serra

We present the results of a large search for intrinsic HI 21 cm and OH 18 cm absorption in 145 compact radio sources in the redshift range 0.02< z <3.8 with the Green Bank Telescope. We re-detect HI 21 cm absorption toward six known…

Astrophysics of Galaxies · Physics 2019-11-27 Kathryn Grasha , Jeremy Darling , Alberto Bolatto , Adam K. Leroy , John T. Stocke

We make a comprehensive study of HI absorption toward HII regions located within Galactic longitudes less than 10 degrees. Structures in the extreme inner Galaxy are traced using the longitude-velocity space distribution of this absorption.…

Astrophysics of Galaxies · Physics 2015-06-16 C. Jones , J. M. Dickey , J. R. Dawson , N. M. McClure-Griffiths , L. D. Anderson , T. M. Bania

The HIDEEP survey (Minchin et al. 2003) was done in an attempt to find objects having low inferred neutral hydrogen column densities, yet they found a distribution which was strongly peaked at 10^20.65 cm^-2. In an attempt to understand…

Spectroscopy of high-redshift compact steep-spectrum (CSS) quasars shows a high incidence of Ly-alpha absorption close to the quasar redshift. Associated absorption systems like these are rare in other types of radio sources, with the…

Astrophysics · Physics 2007-05-23 Joanne C. Baker

The Southern Galactic Plane Survey (SGPS) is a project to image the HI line emission and 1.4 GHz continuum in the fourth quadrant of the Milky Way at high resolution using the Australia Telescope Compact Array (ATCA) and the Parkes Radio…

We report the results of our observations of HI absorption towards the central region of the rejuvenated radio galaxy 4C29.30 (J0840+2949) with the Giant Metrewave Radio Telescope (GMRT). The radio source has diffuse, extended emission with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Yogesh Chandola , D. J. Saikia , Neeraj Gupta

We report the discovery of HI 21-cm absorption towards the well-studied GHz Peaked-Spectrum source CTA 21 (4C 16.09) using the Arecibo Telescope on 2009 September 20 and 21. Recently, the frequency band between 700 and 800 MHz was…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. J. Salter , D. J. Saikia , R. Minchin , T. Ghosh , Y. Chandola

I will review some of the developments in studies of the host galaxy properties of Compact Steep Spectrum (CSS) and GigaHertz-Peaked Spectrum (GPS) radio sources. In contrast to previous reviews structured around observational technique, I…

Astrophysics · Physics 2009-11-13 J. Holt

We present Giant Metrewave Radio Telescope and Very Large Array observations of HI 21-cm absorption in ten z<=0.2 galaxy mergers that host strong radio sources. Seven of these mergers show strong absorption [with N(HI) ~10^{21-22} cm^{-2},…

Astrophysics of Galaxies · Physics 2018-08-01 Rajeshwari Dutta , Raghunathan Srianand , Neeraj Gupta

HI-rich absorbers seen within quasar spectra contain the bulk of neutral gas in the Universe. However, the spatial extent of these reservoirs are not extensively studied due to the pencil beam nature of quasar sightlines. Using two giant…

A standard parametric maximum-likelihood technique is used to determine both the probability distribution over total HI mass $M_{\rm HI}$ and the regression of this quantity on the linear optical diameter $D_{\rm o}$ for field giant spirals…

Astrophysics · Physics 2009-10-28 José M. Solanes , Riccardo Giovanelli , Martha P. Haynes