2003/04/14 by Markos Georganopoulos, Demosthenes Kazanas · 1 citation
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical jet #Astrophysics #Astrophysics and Cosmic Phenomena #Brightness #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geophysics #Hotspot (geology) #Physics #Quasar #Radio Astronomy Observations and Technology #Radio galaxy #Relativistic beaming #Relativistic quantum chemistry #astro-ph
paper · pdf · doi:10.1086/375796
published as Astrophys.J. 589 (2003) L5-L8 · to appear in ApJL
arxiv created 2003/04/14 · openalex publication_date 2003/04/17 · arxiv updated 2016/08/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Pairs of radio-emitting jets with lengths up to several hundred kiloparsecs emanate from the central region (the "core") of radio-loud active galaxies. In the most powerful of them, these jets terminate in the "hot spots," compact high-brightness regions, where the jet flow collides with the intergalactic medium (IGM). Although it has long been established that in their inner (~1 pc) regions these jet flows are relativistic, it is still not clear if they remain so at their largest (hundreds of kiloparsecs) scales. We argue that the X-ray, optical, and radio data of the hot spots, despite their at-first-sight disparate properties, can be unified in a scheme involving a relativistic flow upstream of the hot spot that decelerates to the subrelativistic speed of its inferred advance through the IGM and viewed at different angles to its direction of motion. This scheme, besides providing an account of the hot spot spectral properties with jet orientation, also suggests that the large-scale jets remain relativistic all the way to the hot spots.