A FLARE IN THE JET OF PICTOR A

• Main Authors: Hardcastle, M. J. (Author), Birkinshaw, M. (Author), Croston, J. H. (Author), Evans, Daniel A. (Contributor), Landt, H. (Author), Lenc, Emil (Author), Massaro, F. (Author), Perlman, E. S. (Author), Schwartz, D. A (Author), Siemiginowska, A. (Author), Stawarz, L. (Author), Urry, C. M. (Author), Worrall, D. M. (Author), Marshall, Herman (Author)
• Other Authors: MIT Kavli Institute for Astrophysics and Space Research (Contributor), Marshall, Herman Lee (Contributor)
• Format: Article
• Language: English
• Published: Institute of Physics/American Astronomical Society, 2015-03-04T18:21:22Z.
• Subjects: Article
• Online Access: Get fulltext

A Chandra X-ray imaging observation of the jet in Pictor A showed a feature that appears to be a flare that faded between 2000 and 2002. The feature was not detected in a follow-up observation in 2009. The jet itself is over 150?kpc long and about 1 kpc wide, so finding year-long variability is surprising. Assuming a synchrotron origin of the observed high-energy photons and a minimum energy condition for the outflow, the synchrotron loss time of the X-ray emitting electrons is of order 1200 years, which is much longer than the observed variability timescale. This leads to the possibility that the variable X-ray emission arises from a very small sub-volume of the jet, characterized by a magnetic field that is substantially larger than the average over the jet.
Poland. Ministry of Science and Higher Education (grant N-N203-380336)
Smithsonian Astrophysical Observatory (SAO contract NAS 8-39073)
Chandra X-ray Center (U.S.) (contract NAS8-03060)
Smithsonian Astrophysical Observatory (SAO contract SV3-73016)