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dc.contributor.authorGoodger, Joanna
dc.contributor.authorHardcastle, M.J.
dc.contributor.authorCroston, J.H.
dc.contributor.authorKraft, R.P.
dc.contributor.authorBirkinshaw, M.
dc.contributor.authorEvans, D.A.
dc.contributor.authorJordan, A.
dc.contributor.authorNulsen, P.E.J.
dc.contributor.authorSivakoff, G.R.
dc.contributor.authorWorrall, D.M.
dc.contributor.authorBrassington, Nicola
dc.contributor.authorForman, W.R.
dc.contributor.authorGilfanov, M.
dc.contributor.authorJones, C.
dc.contributor.authorMurray, S.S.
dc.contributor.authorRaychaudhury, S.
dc.contributor.authorSarazin, C.L.
dc.contributor.authorVoss, R.
dc.contributor.authorWoodley, K.A.
dc.date.accessioned2011-12-14T15:01:14Z
dc.date.available2011-12-14T15:01:14Z
dc.date.issued2010
dc.identifier.citationGoodger , J , Hardcastle , M J , Croston , J H , Kraft , R P , Birkinshaw , M , Evans , D A , Jordan , A , Nulsen , P E J , Sivakoff , G R , Worrall , D M , Brassington , N , Forman , W R , Gilfanov , M , Jones , C , Murray , S S , Raychaudhury , S , Sarazin , C L , Voss , R & Woodley , K A 2010 , ' Long-term monitoring of the dynamics and particle acceleration of knots in the jet of Centaurus A ' , The Astrophysical Journal , vol. 708 , no. 1 , pp. 675-697 . https://doi.org/10.1088/0004-637X/708/1/675
dc.identifier.issn0004-637X
dc.identifier.otherPURE: 157749
dc.identifier.otherPURE UUID: 7bf60aa1-9ff7-4a91-b4e5-8bd86ced2e9f
dc.identifier.otherdspace: 2299/4128
dc.identifier.otherScopus: 73449109108
dc.identifier.urihttp://hdl.handle.net/2299/7265
dc.descriptionOriginal article can be found at: http://www.iop.org/EJ/journal/apj Copyright American Astronomical Society [Full text of this article is not available in the UHRA]
dc.description.abstractWe present new and archival multi-frequency radio and X-ray data for Centaurus A obtained over almost 20 years at the Very Large Array and with Chandra, with which we measure the X-ray and radio spectral indices of jet knots, flux density variations in the jet knots, polarization variations, and proper motions. We compare the observed properties with current knot formation models and particle acceleration mechanisms. We rule out impulsive particle acceleration as a formation mechanism for all of the knots as we detect the same population of knots in all of the observations, and we find no evidence of extreme variability in the X-ray knots. We find that the most likely mechanism for all the stationary knots is a collision resulting in a local shock followed by a steady state of prolonged, stable particle acceleration, and X-ray synchrotron emission. In this scenario, the X-ray-only knots have radio counterparts that are too faint to be detected, while the radio-only knots are due to weak shocks where no particles are accelerated to X-ray emitting energies. Although the base knots are prime candidates for reconfinement shocks, the presence of a moving knot in this vicinity and the fact that there are two base knots are hard to explain in this model. We detect apparent motion in three knots; however, their velocities and locations provide no conclusive evidence for or against a faster moving "spine" within the jet. The radio-only knots, both stationary and moving, may be due to compression of the fluid.en
dc.language.isoeng
dc.relation.ispartofThe Astrophysical Journal
dc.titleLong-term monitoring of the dynamics and particle acceleration of knots in the jet of Centaurus Aen
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
rioxxterms.versionofrecordhttps://doi.org/10.1088/0004-637X/708/1/675
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue
herts.rights.accesstyperestrictedAccess


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