2001/05/14 by M. J. Hardcastle · 5 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1051/0004-6361:20010687
5 pages. Accepted for A&A (research note). Uses A&A class file v 5.0.1 (included)
arxiv created 2001/05/14 · openalex publication_date 2001/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Several hotspots of FRII radio sources have previously been detected in the X-ray at a flux level consistent with the X-rays being due to inverse-Compton scattering of radio "synchrotron photons synchrotron self-Compton" , if the magnetic fields in the hotspots are close to their equipartition values. However, the number of hotspots compact and bright enough to exhibit detectable X-ray emission is small, so it is worth searching for synchrotron self-Compton emission in the optical, in spite of the obvious observational difficulties of such an approach. In this note I report on a possible detection of an optical inverse-Compton hotspot in a deep Hubble Space Telescope observation of the distant quasar 3C 196, at a level which implies a hotspot magnetic field strength close to equipartition if the electrons have a low-energy cutoff around .