2005/11/02 by Kiyoaki Wajima, Hayley E. Bignall, Hideyuki Kobayashi +5
Physics and Astronomy · #Active galactic nucleus #Astrophysics and Cosmic Phenomena #Doppler effect #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #Jet (fluid) #Quasar #Sky #Superluminal motion #Very-long-baseline interferometry #astro-ph
paper · pdf · doi:10.1093/pasj/58.2.223
10 pages, 6 figures, 3 tables, to appear in PASJ, Vol.58, No.1
arxiv created 2005/11/02 · openalex publication_date 2006/04/25 · arxiv updated 2015/06/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We made a high-resolution VLBI observation of the gamma-ray loud quasar PKS 1622-297 with the HALCA spacecraft and ground radio telescopes at 5 GHz in 1998 February, almost 3 yr after the source exhibited a spectacular GeV gamma-ray flare. The source shows an elongated structure toward the west on the parsec scale. The visibility data are well modeled by three distinct components: a bright core and two weaker jet components. Comparison with previous observations confirms that the jet components have an apparent superluminal motion up to 12.1 h-1 c, with the inner jet components having lower superluminal speeds. We applied the inverse Compton catastrophe model and derived a Doppler factor, δ, of 2.45, which is rather lower than those of other gamma-ray loud active galactic nuclei (AGNs), suggesting that the source was in a more quiescent phase at the epoch of our observation. As an alternative probe of the subparsec-scale structure, we also present the results from multiepoch ATCA total flux monitoring, which indicate the presence of persistent intraday variability consistent with refractive interstellar scintillation. We examined the gamma-ray emission mechanism in light of these observations.