Show simple item record

dc.contributor.authorLintott, C.
dc.contributor.authorSchawinski, K.
dc.contributor.authorKeel, W.
dc.contributor.authorVan Arkel, H.
dc.contributor.authorBennert, N.
dc.contributor.authorEdmondson, E.
dc.contributor.authorThomas, D.
dc.contributor.authorSmith, Daniel
dc.contributor.authorHerbert, P.D.
dc.contributor.authorJarvis, M.J.
dc.contributor.authorVirani, S.
dc.contributor.authorAndreescu, D.
dc.contributor.authorBamford, S.
dc.contributor.authorLand, K.
dc.contributor.authorMurray, P.
dc.contributor.authorNichol, R.C.
dc.contributor.authorRaddick, M.J.
dc.contributor.authorSlosar, A.
dc.contributor.authorSzalay, A.
dc.contributor.authorVandenberg, J.
dc.date.accessioned2010-02-26T13:36:24Z
dc.date.available2010-02-26T13:36:24Z
dc.date.issued2009
dc.identifier.citationLintott , C , Schawinski , K , Keel , W , Van Arkel , H , Bennert , N , Edmondson , E , Thomas , D , Smith , D , Herbert , P D , Jarvis , M J , Virani , S , Andreescu , D , Bamford , S , Land , K , Murray , P , Nichol , R C , Raddick , M J , Slosar , A , Szalay , A & Vandenberg , J 2009 , ' Galaxy Zoo: Hanny's Voorwerp, a quasar light echo? ' , Monthly Notices of the Royal Astronomical Society , vol. 399 , no. 1 , pp. 129-140 . https://doi.org/10.1111/j.1365-2966.2009.15299.x
dc.identifier.issn0035-8711
dc.identifier.otherPURE: 176961
dc.identifier.otherPURE UUID: 1bd5ccb6-388b-4e74-8d72-fe7029d7ba59
dc.identifier.otherdspace: 2299/4317
dc.identifier.otherScopus: 70349661785
dc.identifier.urihttp://hdl.handle.net/2299/4317
dc.description‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2009.15299.x
dc.description.abstractWe report the discovery of an unusual object near the spiral galaxy IC 2497, discovered by visual inspection of the Sloan Digital Sky Survey (SDSS) as part of the Galaxy Zoo project. The object, known as Hanny's Voorwerp, is bright in the SDSS g band due to unusually strong [O iii]4959, 5007 emission lines. We present the results of the first targeted observations of the object in the optical, ultraviolet and X-ray, which show that the object contains highly ionized gas. Although the line ratios are similar to extended emission-line regions near luminous active galactic nucleus (AGN), the source of this ionization is not apparent. The emission-line properties, and lack of X-ray emission from IC 2497, suggest either a highly obscured AGN with a novel geometry arranged to allow photoionization of the object but not the galaxy's own circumnuclear gas, or, as we argue, the first detection of a quasar light echo. In this case, either the luminosity of the central source has decreased dramatically or else the obscuration in the system has increased within 105 yr. This object may thus represent the first direct probe of quasar history on these time-scales.en
dc.language.isoeng
dc.relation.ispartofMonthly Notices of the Royal Astronomical Society
dc.rightsOpen
dc.titleGalaxy Zoo: Hanny's Voorwerp, a quasar light echo?en
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.description.statusPeer reviewed
dc.relation.schoolSchool of Physics, Astronomy and Mathematics
dcterms.dateAccepted2009
rioxxterms.versionofrecordhttps://doi.org/10.1111/j.1365-2966.2009.15299.x
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue
herts.rights.accesstypeOpen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record