Observations of HI absorbing gas in compact radio sources at cosmological redshifts

Show simple item record

dc.contributor.author Vermeulen, Rene en_US
dc.contributor.author Pihlstroem, Ylva en_US
dc.contributor.author Tschager, Wolfgang en_US
dc.contributor.author de Vries, Wim en_US
dc.contributor.author Conway, John en_US
dc.contributor.author Barthel, Peter en_US
dc.contributor.author Baum, Stefi en_US
dc.contributor.author Braun, Robert en_US
dc.contributor.author Bremer, Martin en_US
dc.contributor.author Miley, George en_US
dc.contributor.author O'Dea, Christopher en_US
dc.contributor.author Rottgering, Huub en_US
dc.contributor.author Schilizzi, Richard en_US
dc.contributor.author Snellen, Ignas en_US
dc.contributor.author Taylor, Gregory en_US
dc.date.accessioned 2006-05-11T18:00:27Z en_US
dc.date.available 2006-05-11T18:00:27Z en_US
dc.date.issued 2003-06-04 en_US
dc.identifier.citation Astronomy and Astrophysics 404 (2003) 861-870 en_US
dc.identifier.issn 1432-0746 en_US
dc.identifier.uri http://hdl.handle.net/1850/1789 en_US
dc.description Also archived in: arXiv: astro-ph/0304291 v1 15 Apr 2003 en_US
dc.description.abstract We present an overview of the occurrence and properties of atomic gas associated with compact radio sources at redshifts up to z = 0.85. Searches for Hi 21 cm absorption were made with the Westerbork Synthesis Radio Telescope at UHF-high frequencies (725–1200 MHz). Detections were obtained for 19 of the 57 sources with usable spectra (33%). We have found a large range in line depths, from r = 0.16 to r<= 0.001. There is a substantial variety of line profiles, including Gaussians of less than 10 kms^−1, to more typically 150 kms^−1, as well as irregular and multi-peaked absorption profiles, sometimes spanning several hundred kms^−1. Assuming uniform coverage of the entire radio source, we obtain column depths of atomic gas between 1×10^19 and 3.3×10^21 (Tsp/100 K)(1/f) cm^−2. There is evidence for significant gas motions, but in contrast to earlier results at low redshift, there are many sources in which the Hi velocity is substantially negative (up to v = −1420 kms^−1) with respect to the optical redshift, suggesting that in these sources the atomic gas, rather than falling into the centre, may be be flowing out, interacting with the jets, or rotating around the nucleus (Refer to PDF file for exact formulas). en_US
dc.description.sponsorship The WSRT is operated by ASTRON (The Netherlands Foundation for Research in Astronomy) with support from the Netherlands Foundation for Scientific Research (NWO). We are very grateful for the dedication of the ASTRON staff who worked on the WSRT upgrade, as well as those who assisted in performing the survey observations. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration in the United States of America. en_US
dc.format.extent 1023424 bytes en_US
dc.format.mimetype application/pdf en_US
dc.language.iso en_US en_US
dc.publisher Astronomy and Astrophysics en_US
dc.relation.ispartofseries vol. 404 en_US
dc.relation.ispartofseries no. 3 en_US
dc.relation.ispartofseries pps. 861-870 en_US
dc.subject Galaxies-active en_US
dc.subject Galaxies-evolution en_US
dc.subject Galaxies-ISM en_US
dc.subject Radio lines-galaxies en_US
dc.title Observations of HI absorbing gas in compact radio sources at cosmological redshifts en_US
dc.type Article en_US

Files in this item

Files Size Format View
SBaumArticle06-04-03.pdf 1.023Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record

Search RIT DML


Advanced Search

Browse