ATCA observation of LMC X-3
ATel #1138; E. Gallo (UCSB), T. Tzioumis (ATNF)
on 10 Jul 2007; 21:13 UT
Credential Certification: Elena Gallo (elena@physics.ucsb.edu)
Subjects: Radio, Black Hole, Transient
Prompted by its recent transition to a faint hard X-ray state (ATEL#1122), we observed the extra-galactic high mass black hole X-ray binary LMC X-3 with the Compact Array on July 9.79 UTC. We did not detect a radio counterpart down to an rms noise level of 0.05 mJy/beam at 4.8 GHz.
In terms of luminosity, the inferred 3-sigma upper limit to the possible radio counterpart of LMC X-3 (< 0.15 mJy at 55 kpc) is at least 5 times weaker than the Galactic black hole GRS 1915+105 while in the plateau state (20 mJy at 11 kpc), but still 7 times higher than Cygnus X-1 while in the hard state (15 mJy at 2 kpc).