1994/02/18 by J. G. Skibo, J. B. Skibo, C. D. Dermer +1 · 29 citations
Physics and Astronomy · #Active galactic nucleus #Astrophysical Phenomena and Observations #Astrophysical jet #Astrophysics and Cosmic Phenomena #Centaurus A #Degree of polarization #Gamma-ray bursts and supernovae #Jet (fluid) #Line-of-sight #Photon #Polarization (electrochemistry) #Radiation #astro-ph
paper · pdf · doi:10.1086/187330
published in The Astrophysical Journal 426, L23 (IOP Publishing) · 12 pages, Postscript file with 3 Figures, NRL 017-331-094
arxiv created 1994/02/18 · openalex publication_date 1994/05/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider whether the hard X-ray and soft gamma-ray emission from Centaurus A is beamed radiation from the active nucleus that is Compton- scattered into our line of sight. We derive the spectrum and degree of polarization of scattered radiation when incident beamed radiation is scattered from a cold (kT << mec2^) electron cloud moving with bulk relativistic motion along the jet axis, and calculate results for an unpolarized, highly beamed incident power-law photon source. We fit the OSSE data from Centaurus A with this model and find that if the scatterers are not moving relativistically, then the angle the jet makes with respect to our line of sight is 61deg^ + 5deg^. We predict a high degree of polarization of the scattered radiation below ~300 keV. Future measurements with X-ray and gamma-ray polarimeters could be used to constrain or rule out such a scenario.