12mm line survey of the dense molecular gas towards the W28 field TeV gamma-ray sources

dc.contributor.authorNicholas, B.
dc.contributor.authorRowell, G.
dc.contributor.authorBurton, M.
dc.contributor.authorWalsh, A.
dc.contributor.authorFukui, Y.
dc.contributor.authorKawamura, A.
dc.contributor.authorLongmore, S.
dc.contributor.authorKeto, E.
dc.date.issued2011
dc.description.abstractWe present 12 mm Mopra observations of dense molecular gas towards the W28 supernova remnant (SNR) field. The focus is on the dense molecular gas towards the TeV gamma-ray sources detected by the HESS telescopes, which likely trace the cosmic rays from W28 and possibly other sources in the region. Using the NH3 inversion transitions we reveal several dense cores inside the molecular clouds, the majority of which coincide with high-mass star formation and H ii regions, including the energetic ultracompact H ii region G5.89−0.39. A key exception to this is the cloud north-east of W28, which is well known to be disrupted as evidenced by clusters of 1720 MHz OH masers and broad CO line emission. Here we detect broad NH3, up to the (9,9) transition, with linewidths up to 16 km s−1. This broad NH3 emission spatially matches well with the TeV source HESS J1801−233 and CO emission, and its velocity dispersion distribution suggests external disruption from the W28 SNR direction. Other lines are detected, such as HC3N and HC5N, H2O masers, and many radio recombination lines, all of which are primarily found towards the southern high-mass star formation regions. These observations provide a new view on to the internal structures and dynamics of the dense molecular gas towards the W28 SNR field and, in tandem with future higher-resolution TeV gamma-ray observations, will offer the chance to probe the transport of cosmic rays into molecular clouds.
dc.description.statementofresponsibilityB. Nicholas, G. Rowell, M. G. Burton, A. Walsh, Y. Fukui, A. Kawamura, S. Longmore and E. Keto
dc.identifier.citationMonthly Notices of the Royal Astronomical Society, 2011; 411(2):1367-1385
dc.identifier.doi10.1111/j.1365-2966.2010.17778.x
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.orcidRowell, G. [0000-0002-9516-1581]
dc.identifier.urihttp://hdl.handle.net/2440/63144
dc.language.isoen
dc.publisherBlackwell Publishing Ltd
dc.relation.granthttp://purl.org/au-research/grants/arc/DP0662810
dc.relation.granthttp://purl.org/au-research/grants/arc/DP0662810
dc.rights© 2010 The Authors Monthly Notices of the Royal Astronomical Society © 2010 RAS
dc.source.urihttps://doi.org/10.1111/j.1365-2966.2010.17778.x
dc.subjectmolecular data
dc.subjectsupernovae: individual: W28
dc.subjectISM: clouds
dc.subjectcosmic rays
dc.subjectHII regions
dc.subjectgamma rays: ISM
dc.subjectradio lines: ISM.
dc.title12mm line survey of the dense molecular gas towards the W28 field TeV gamma-ray sources
dc.typeJournal article
pubs.publication-statusPublished

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