Show simple item record

dc.contributor.authorBroderick, Avery E.
dc.contributor.authorFish, Vincent L.
dc.contributor.authorLoeb, Abraham
dc.contributor.authorDoeleman, Sheperd Samuel
dc.date.accessioned2015-03-12T20:42:19Z
dc.date.available2015-03-12T20:42:19Z
dc.date.issued2009-05
dc.date.submitted2008-09
dc.identifier.issn0004-637X
dc.identifier.issn1538-4357
dc.identifier.urihttp://hdl.handle.net/1721.1/96006
dc.description.abstractRecent millimeter-VLBI observations of Sagittarius A* (Sgr A*) have, for the first time, directly probed distances comparable to the horizon scale of a black hole. This provides unprecedented access to the environment immediately around the horizon of an accreting black hole. We leverage both existing spectral and polarization measurements and our present understanding of accretion theory to produce a suite of generic radiatively inefficient accretion flow (RIAF) models of Sgr A*, which we then fit to these recent millimeter-VLBI observations. We find that if the accretion flow onto Sgr A* is well described by an RIAF model, the orientation and magnitude of the black hole's spin are constrained to a two-dimensional surface in the spin, inclination, position angle parameter space. For each of these, we find the likeliest values and their 1σ and 2σ errors to be a = 0[superscript +0.4 +0.7], ϴ = 50° [superscript +10° +30° subscript -10° -10°] and ξ = -20° [superscript +31° +107° subscript -16° -29°], when the resulting probability distribution is marginalized over the others. The most probable combination is a = 0+0.2+0.4, ϴ =90° [subscript -40° -50°], and ξ = -14° [superscript +7° +11° subscript -7° -11°], though the uncertainties on these are very strongly correlated, and high probability configurations exist for a variety of inclination angles above 30° and spins below 0.99. Nevertheless, this demonstrates the ability millimeter-VLBI observations, even with only a few stations, to significantly constrain the properties of Sgr A*.en_US
dc.language.isoen_US
dc.publisherIOP Publishingen_US
dc.relation.isversionofhttp://dx.doi.org/10.1088/0004-637x/697/1/45en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourceAmerican Astronomical Societyen_US
dc.titleESTIMATING THE PARAMETERS OF SAGITTARIUS A*'s ACCRETION FLOW VIA MILLIMETER VLBIen_US
dc.typeArticleen_US
dc.identifier.citationBroderick, Avery E., Vincent L. Fish, Sheperd S. Doeleman, and Abraham Loeb. “ESTIMATING THE PARAMETERS OF SAGITTARIUS A*’s ACCRETION FLOW VIA MILLIMETER VLBI.” The Astrophysical Journal 697, no. 1 (April 30, 2009): 45–54. © 2009 The American Astronomical Societyen_US
dc.contributor.departmentHaystack Observatoryen_US
dc.contributor.mitauthorFish, Vincent L.en_US
dc.contributor.mitauthorDoeleman, Sheperd Samuelen_US
dc.relation.journalAstrophysical Journalen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsBroderick, Avery E.; Fish, Vincent L.; Doeleman, Sheperd S.; Loeb, Abrahamen_US
mit.licensePUBLISHER_POLICYen_US
mit.metadata.statusComplete


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record