New results on particle acceleration in the Centaurus A jet and counterjet from a deep Chandra observation
Abstract
We present new deep Chandra observations of the Centaurus A jet, with a combined on-source exposure time of 719 ks. These data allow detailed X-ray spectral measurements to be made along the jet out to its disappearance at 4.5 kpc from the nucleus. We distinguish several regimes of high-energy particle acceleration: while the inner part of the jet is dominated by knots and has properties consistent with local particle acceleration at shocks, the particle acceleration in the outer 3.4 kpc of the jet is likely to be dominated by an unknown distributed acceleration mechanism. In addition to several compact counterjet features we detect probable extended emission from a counterjet out to 2.0 kpc from the nucleus, and argue that this implies that the diffuse acceleration process operates in the counterjet as well. A preliminary search for X-ray variability finds no jet knots with dramatic flux density variations, unlike the situation seen in M87.
Keywords
Cite
@article{arxiv.0710.1277,
title = {New results on particle acceleration in the Centaurus A jet and counterjet from a deep Chandra observation},
author = {M. J. Hardcastle and R. P. Kraft and G. R. Sivakoff and J. L. Goodger and J. H. Croston and A. Jordan and D. A. Evans and D. M. Worrall and M. Birkinshaw and S. Raychaudhury and N. J. Brassington and W. R. Forman and W. E. Harris and C. Jones and A. M. Juett and S. S. Murray and P. E. J. Nulsen and C. L. Sarazin and K. A. Woodley},
journal= {arXiv preprint arXiv:0710.1277},
year = {2009}
}
Comments
ApJ L accepted. 4 pages, 4 figures. Some figures reduced in quality, publication-quality version available at http://hercules.herts.ac.uk/~mjh/cena-jet.pdf