Where Centaurus A gets its X-ray knottiness
Worrall, D.M.; Birkinshaw, M.; Kraft, R.P.; Sivakoff, G.R.; Jordan, A.; Hardcastle, M.J.; Brassington, Nicola; Croston, J.H.; Evans, D.A.; Forman, W.R.; Harris, W.E.; Jones, C.; Juett, A.M.; Murray, S.S.; Nulsen, P.E.J.; Raychaudhury, S.; Sarazin, C.L.; Woodley, K.A.
Citation: Worrall , D M , Birkinshaw , M , Kraft , R P , Sivakoff , G R , Jordan , A , Hardcastle , M J , Brassington , N , Croston , J H , Evans , D A , Forman , W R , Harris , W E , Jones , C , Juett , A M , Murray , S S , Nulsen , P E J , Raychaudhury , S , Sarazin , C L & Woodley , K A 2008 , ' Where Centaurus A gets its X-ray knottiness ' Astrophysical Journal , vol 673 , pp. L135-L138 .
We report an X-ray spectral study of the transverse structure of the Centaurus A jet using new data from the Chandra Cen A Very Large Project. We find that the spectrum steepens with increasing distance from the jet axis, and that this steepening can be attributed to a change in the average spectrum of the knotty emission. Such a trend is unexpected if the knots are predominantly a surface feature residing in a shear layer between faster and slower flows. We suggest that the spectral steepening of the knot emission as a function of distance from the jet axis is due to knot migration, implying a component of transverse motion of knots within the flow.
Original article can be found at: http://www.iop.org/EJ/journal/apjl Copyright American Astronomical Society DOI: 10.1086/528681 [Full text of this article is not available in the UHRA]