Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/1400
Full metadata record
DC FieldValueLanguage
dc.contributor.authorDwarakanath, K.S.-
dc.contributor.authorVan Gorkom, J.H.-
dc.contributor.authorOwen, F.N.-
dc.date.accessioned2006-07-07T06:04:54Z-
dc.date.available2006-07-07T06:04:54Z-
dc.date.issued1994-09-
dc.identifier.citationAstrophysical Journal, 1994, Vol.432, p469-477en
dc.identifier.issn0004-637X-
dc.identifier.issn1538-4357 (online)-
dc.identifier.urihttp://hdl.handle.net/2289/1400-
dc.description.abstractWe present a Very Large Array (VLA) search for neutral hydrogen in three clusters, which are considered to be prime examples of so-called cooling flow clusters: Virgo (Virgo A), Abell 2199 (3C 338), and Abell 780 (Hydra A). We looked for H I in absorption against the central radio sources with a velocity coverage approximately 2600 km/s and with a velocity resolution approximately 87 km/s. We do not detect a spatially extended distribution of cold clouds. Our 3 sigma optical depth limits are 0.0005 over a typical velocity range of 500 km/s. Assuming the currently popular cooling flow scenarios in which the distribution of the cold gas can be characterized by a core radius of approximately 100 kpc, our results place an upper limit of 1.2 x 1010 solar mass to the mass of neutral hydrogen in such a flow for an assumed spin temperature of 100 K. This limit is a factor of 30 below what is expected from the Einstein Solid State Spectrometer observations of cooling flow clusters and is 1-2 orders of magnitude below what is expected from the cooling flow models. The expected large amount of H I is unlikely to exist in these clusters even as optically thick clouds unless their spin temperature is less than 10 K and/or their covering factor is much less than 1. We discuss some physical conditions in which the expected large amounts of H I could have escaped detection. We do, however, find H I absorption against the core of Hydra A. This line is narrow (approximately 50 kms) and is not seen against the extended radio lobes. The properties of this absorption system are similar to those seen in some other cooling flow clusters and in isolated radio galaxies. We also detect a spiral galaxy in A 2199 with a total mass of 1.8 x 109 solar mass. Despite this detection of what might be a small H I cloud near the systemic velocity of the core of Hydra A, we do place stringent limits on the existence of such clouds anywhere within the primary beam. The upper limit to H I emission from such clouds ranges from 107 to 109 solar mass.en
dc.format.extent1634114 bytes-
dc.format.mimetypeapplication/pdf-
dc.language.isoenen
dc.publisherThe University of Chicago Press for the American Astronomical Societyen
dc.relation.urihttp://adsabs.harvard.edu/cgi-bin/bib_query?1994ApJ...432..469Den
dc.rights(1994) by the American Astronomical Society. Scanned images provided by the NASA ADS Data System.en
dc.subjectCOOLING FLOWS (ASTROPHYSICS)en
dc.subjectGALACTIC CLUSTERSen
dc.subjectH LINES, HYDROGENen
dc.subjectINTERGALACTIC MEDIAen
dc.subjectRADIO SOURCES (ASTRONOMY)en
dc.subjectVELOCITY DISTRIBUTIONen
dc.subjectX RAY ABSORPTIONen
dc.subjectBRIGHTNESS DISTRIBUTIONen
dc.subjectVERY LARGE ARRAY (VLA)en
dc.subjectX RAY ASTRONOMYen
dc.titleA VLA search for neutral hydrogen in cooling flow clustersen
dc.typeArticleen
Appears in Collections:Research Papers (A&A)

Files in This Item:
File Description SizeFormat 
1994 ApJ V432 p469.pdf9p.1.6 MBAdobe PDFView/Open


Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.