2005/11/22 by B. G. Piner, D. Bhattarai, P. G. Edwards +1 · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Blazar #Doppler effect #Egret #Limit (mathematics) #Lorentz factor #Neutrino Physics Research #Quantum and Classical Electrodynamics #Relativistic beaming #Superluminal motion #Very Long Baseline Array #astro-ph
paper · pdf · doi:10.1086/500006
published as Astrophys.J.640:196-203,2006 · Accepted to ApJ, 8 pages, 1 color figure
arxiv created 2005/11/22 · openalex publication_date 2006/03/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have measured peak apparent speeds of 25.6 c ± 7.0 c , 25.6 c ± 4.4 c , and 28.2 c ± 6.6 c in the jets of 0235+164, 0827+243, and 1406-076, respectively, based on six epochs of high-sensitivity VLBA observations at 22 and 43 GHz during 2002 and 2003 ( H 0 = 71 km s -1 Mpc -1 , Ω m = 0.27, and Ω Λ = 0.73). These blazars had been identified as potentially having apparent speeds exceeding 40 c in an earlier VLBA survey of EGRET blazars by Jorstad and coworkers. We therefore confirm (with high confidence in 0827+243, and lower confidence in 0235+164 and 1406-076) the presence of highly relativistic pattern speeds in these three jets, although not at the >40 c levels reported by Jorstad and coworkers. The lower limit to the bulk Lorentz factor implied by the observed apparent speeds is Γ ≳ 25-30 in these three sources, if the pattern speeds are equal to or slower than the bulk flow speed.