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dc.contributor.authorGrandi, P.
dc.contributor.authorUrry, C.M.
dc.contributor.authorMaraschi, L.
dc.contributor.authorWehrle, A. E.
dc.contributor.authorMadejski, G. M.
dc.contributor.authorAller, M. F.
dc.contributor.authorAller, H. D.
dc.contributor.authorBailyn, C. D.
dc.contributor.authorBalonek, T.J.
dc.contributor.authorBock, T. H.
dc.contributor.authorGlass, I. S.
dc.contributor.authorLitchfield, S.J.
dc.contributor.authorMcHardy, I.M.
dc.contributor.authorMulchaey, J. S.
dc.contributor.authorReuter, H.-P.
dc.contributor.authorRobson, E. I.
dc.contributor.authorSadun, A. C.
dc.contributor.authorSherry, W.
dc.contributor.authorSteppe, H.
dc.contributor.authorStevens, Jason
dc.contributor.authorTeraesranta, H.
dc.contributor.authorTornikoski, M.
dc.contributor.authorWagner, S.J.
dc.date.accessioned2012-01-30T16:01:02Z
dc.date.available2012-01-30T16:01:02Z
dc.date.issued1996-03-01
dc.identifier.citationGrandi , P , Urry , C M , Maraschi , L , Wehrle , A E , Madejski , G M , Aller , M F , Aller , H D , Bailyn , C D , Balonek , T J , Bock , T H , Glass , I S , Litchfield , S J , McHardy , I M , Mulchaey , J S , Reuter , H-P , Robson , E I , Sadun , A C , Sherry , W , Steppe , H , Stevens , J , Teraesranta , H , Tornikoski , M & Wagner , S J 1996 , ' 3C 279 Multiwavelength Monitoring II : The Ground-based Campaign ' , The Astrophysical journal , vol. 459 , pp. 73-81 . https://doi.org/10.1086/176869
dc.identifier.issn0004-637X
dc.identifier.otherPURE: 522335
dc.identifier.otherPURE UUID: 505e0fb1-0115-43b3-b75b-f6d4e4a8ccd5
dc.identifier.otherBibtex: urn:fe39d2c14a28ae4dfbc914fd40206690
dc.identifier.otherScopus: 21344443670
dc.identifier.otherORCID: /0000-0002-4010-8310/work/62747537
dc.identifier.urihttp://hdl.handle.net/2299/7742
dc.description.abstractThe optically violently variable quasar 3C 279 was monitored simultaneously from radio to y-ray frequencies in 1992 December-1993 January. We report a detailed study of the ground-based results from radio to optical wavelengths. These data show that 3C 279 has a typical blazar spectrum, slightly rising at radio frequency and then progressively steeper above a first turnover frequency between 37 and 90 GHz. In the millimeter wavelength region, a simple power law is not an adequate description of the spectrum. We suggest that the millimeter "shoulder" corresponds to an additional emission component, self-absorbed between 150 and 375 GHz, possibly associated with the detachment of a new VLBI knot and with the start of radio flare. A flux increase of 20% over 20 days was observed at 37 and 90 GHz, while contemporaneously the R-band flux doubled in about two weeks. The lack of strong variability in contemporaneous X-ray light curves (possible X-ray variations are less than 30%) implies no direct (i.e., zero lag) correlation between the optical and X-ray fluxes. If X-rays are produced by inverse-Compton scattering of relativistic electrons on some seed photons, the above results exclude that the observed optical photons are the seeds and/or that the relativistic electrons radiating via synchrotron in the optical band are responsible for the scattering to X-ray energies. We suggest that the X-rays are instead produced through the inverseCompton process by electrons of lower energy, which radiate via synchrotron in the radio to millimeter wave bands and which scatter either on the synchrotron photons themselves or on external photons.en
dc.language.isoeng
dc.relation.ispartofThe Astrophysical journal
dc.subjectGALAXIES: PHOTOMETRY, GAMMA RAYS: OBSERVATIONS, GALAXIES: QUASARS: INDIVIDUAL ALPHANUMERIC: 3C 279, RADIATION MECHANISMS: NONTHERMAL, X-RAYS: GALAXIES
dc.title3C 279 Multiwavelength Monitoring II : The Ground-based Campaignen
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.contributor.institutionScience & Technology Research Institute
dc.contributor.institutionCentre for Astrophysics Research
dc.description.statusPeer reviewed
dc.relation.schoolSchool of Physics, Astronomy and Mathematics
dcterms.dateAccepted1996-03-01
rioxxterms.versionofrecordhttps://doi.org/10.1086/176869
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue


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