Open AccessA relativistic jet from Cygnus X‐1 in the low/hard X‐ray state
Author(s) -
Stirling A.M.,
Spencer R.E.,
De La Force C.J.,
Garrett M.A.,
Fender R.P.,
Ogley R.N.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04821.x
Subject(s) - physics , very long baseline array , astrophysics , jet (fluid) , core (optical fiber) , polarization (electrochemistry) , x ray , astrophysical jet , active galactic nucleus , linear polarization , black hole (networking) , astronomy , x ray binary , neutron star , galaxy , optics , laser , chemistry , thermodynamics , computer network , routing protocol , routing (electronic design automation) , computer science , link state routing protocol
We present the detection of a radio‐emitting jet from the black hole candidate and X‐ray binary source Cygnus X‐1. Evidence of a bright core with a slightly extended structure was found on milliarcsecond resolution observations with the Very Long Baseline Array (VLBA) at 15.4 GHz. Later observations with the VLBA [and including the phased‐up, Very Large Array (VLA)] at 8.4 GHz show an extended jet‐like feature extending to ∼ 15 mas from a core region, with an opening angle of < 2°. In addition, lower resolution MERLIN observations at 5 GHz show that the source has < 10 per cent linear polarization. The source was in the low/hard X‐ray state during the observations, and the results confirm the existence of persistent radio emission from an unresolved core and a variable, relativistic (> 0.6 c ) jet during this state.