2007/12/30 by R. A. Laing, Laing, R. A., A. H. Bridle +7
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.0801.0154
5 pages, 3 figures, to appear in Extragalactic Jets: Theory and Observation from Radio to Gamma Ray, T. A. Rector and D. S. De Young (eds.), ASP Conference Series
arxiv created 2007/12/30 · arxiv updated 2009/12/01
We describe very accurate imaging of radio spectral index for the inner jets in three FR I radio galaxies. Where the jets first brighten, there is a remarkably small dispersion around a spectral index of 0.62. This is also the region where bright X-ray emission is detected. Further from the nucleus, the spectral index flattens slightly to 0.50 - 0.55 and X-ray emission, although still detectable, is fainter relative to the radio. The brightest X-ray emission from the jets is therefore not associated with the flattest radio spectra, but rather with some particle-acceleration process whose characteristic energy index is 2.24. The change in spectral index occurs roughly where our relativistic jet models require rapid deceleration. Flatter-spectrum edges can be seen where the jets are isolated from significant surrounding diffuse emission and we suggest that these are associated with shear.