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dc.contributor.authorVlemmings, Wouter
dc.contributor.authorBignall, Hayley
dc.contributor.authorDiamond, Phil
dc.date.accessioned2017-01-30T13:01:35Z
dc.date.available2017-01-30T13:01:35Z
dc.date.created2012-12-03T07:24:55Z
dc.date.issued2007
dc.date.submitted2014-01-07
dc.identifier.citationVlemmings, W.H.T. and Bignall, H.E. and Diamond, P.J. 2007. Green bank telescope observations of the water masers of NGC 3079: Accretion disk magnetic field and maser scintillation. The Astrophysical Journal 656 (1): pp. 198-205.
dc.identifier.urihttp://hdl.handle.net/20.500.11937/27844
dc.identifier.doi10.1086/510515
dc.description.abstract

We present observations of the 22 GHz H2O megamasers in the circumnuclear disk of NGC 3079 obtained with the Green Bank Telescope. The data are analyzed for circular polarization due to the Zeeman-induced splitting of the H2O maser lines. No circular polarization is detected, and we derive a 1 upper limit of 11 mG for the toroidal magnetic field at 0.64 pc from the central black hole. This is the tightest upper limit for the magnetic field around a black hole to date. We use the magnetic field limit to derive an estimate of the mass accretion onto the central black hole. In addition to the polarimetric results, we present an observation of rapid variability in the maser lines, which we explain as weak interstellar scintillation. From the scintillation parameters, we estimate an intrinsic size of the mostly saturated maser features of 12 as. This is consistent with models assuming a thick, clumpy accretion disk.

dc.publisherThe American Astronomical Society
dc.subjectgalaxies: individual (NGC 3079)
dc.subjectscattering
dc.subjectmasers
dc.subjectmagnetic fields
dc.titleGreen bank telescope observations of the water masers of NGC 3079: Accretion disk magnetic field and maser scintillation
dc.typeJournal Article
dcterms.dateSubmitted2012-12-03
dcterms.source.volume656
dcterms.source.startPage198
dcterms.source.endPage205
dcterms.source.issn0004637X
dcterms.source.titleThe Astrophysical Journal
curtin.digitool.pid188220
curtin.pubStatusPublished
curtin.department
curtin.identifier.scriptidPUB-SE-DAP-TMC-53753
curtin.accessStatusFulltext not available


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