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The Outburst of HST-1 in the M87 Jet

D. E. Harris·C. C. Cheung·J. A. Biretta·W. Sparks·W. Junor·E. S. Perlman·A. S. Wilson
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Abstract

The X-ray intensity of knot HST-1, 0.85" from the nucleus of the radio galaxy M87, has increased by more than a factor of 50 during the last 5 years. The optical increase is similar and our more limited radio data indicate a commensurate activity. We give the primary results of our Chandra X-ray Observatory monitoring program and consider some of the implications of this extreme variability in a relativistic jet. We find that the data support a 'modest beaming synchrotron' model as indicated in our earlier papers. Based on this model, the decay of the X-ray lightcurve appears to be dominated by light travel time across the emitting region of HST-1, rather than synchrotron loss timescales.

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D. E. Harris, C. C. Cheung, J. A. Biretta, W. Sparks, W. Junor, E. S. Perlman, A. S. Wilson. 2005-11-28. The Outburst of HST-1 in the M87 Jet. https://doi.org/10.1086/500081

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