[ Previous | Next | ADS ]

Radio observation of the X-ray pulsar GRO J1008-57 during outburst

ATel #653; Simone Migliari (UCSD), Bob Sault (ATNF), John Tomsick (UCSD)
on 8 Nov 2005; 19:11 UT
Credential Certification: Simone Migliari (migliari@science.uva.nl)

Subjects: Radio, X-ray, Binary, Black Hole, Neutron Star, Transient

Australia Telescope Compact Array (ATCA) radio observations of the transient X-ray pulsar GRO J1008-57 during its X-ray outburst (ATEL #647), taken at 8.6 GHz on November 6, have detected no radio counterpart with a flux density 1-sigma sensitivity of 41 microJy/beam. Based on the weighted average of the dwell count rate measured by the All-Sky Monitor on board the Rossi X-ray Timing Explorer, during the ATCA observations the 1.5-12 keV X-ray flux was about 4x10^-10 erg/s cm^2. Given an estimated distance of 5 kpc (Coe et al. 1994, MNRAS, 270, L57), the 3-sigma radio upper limit, although significantly lower than the radio luminosities observed in black hole X-ray binaries, is still consistent with the radio detections of low-magnetic field neutron star X-ray binaries at the same X-ray luminosity (see Fig. 2 and Fig. 3 in Migliari & Fender 2005, MNRAS, in press: astro-ph/0510698). The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.