The luminous X-ray hotspot in 4C 74.26: synchrotron or inverse-Compton emission?

Journal article

We report the discovery of an X-ray counterpart to the southern radio hotspot of the largest-known radio quasar 4C 74.26 (whose redshift is z=0.104). Both XMM-Newton and Chandra images reveal the same significant (10arcsec, i.e. 19kpc) offset between the X-ray hotspot and the radio hotspot imaged with MERLIN. The peak of the X-ray emission may be due to synchrotron or inverse-Compton emission. If synchrotron emission, the hotspot represents the site of particle acceleration and the offset arises from either the jet exhibiting Scheuer's `dentist's drill' effect or a fast spine having less momentum than the sheath surrounding it, which creates the radio hotspot. If the emission arises from the inverse-Compton process, it must be inverse-Compton scattering of the CMB in a decelerating relativistic flow, implying that the jet is relativistic (Gamma >= 2) out to a distance of at least 800kpc. Our analysis, including optical data from the Liverpool Telescope, rules out a background AGN for the X-ray emission and confirms its nature as a hotspot, making it the most X-ray luminous hotspot yet detected.

Authors: Erlund, M; Fabian, A; Blundell, K; Moss, C; Ballantyne, DR

• Publication status: Published
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 379
• Issue: 2
• Pages: 498-506
• Publication date: 2007-05-09
• DOI: 10.1111/j.1365-2966.2007.11962.x
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: astro-ph