A New Radio Detection of the Bursting Source GCRT J1745-3009

Scott D. Hyman T. Joseph W. Lazio Subhashis Roy Paul S. Ray Namir E. Kassim

(1) Department of Physics and Engineering, Sweet Briar College, Sweet Briar, VA 24595
(2) Remote Sensing Division, Naval Research Laboratory, Washington, DC 20375-5351
(3) ASTRON, P.O. Box 2, 7990 AA Dwingeloo, The Netherlands.
(4) E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC 20375-5352
(5) Remote Sensing Division, Naval Research Laboratory, Washington, DC 20375-5351

Paper: ApJ, submitted

EPrint Server: astro-ph/0508264


GCRT J1745-3009 is a transient bursting radio source located in the direction of the Galactic center, discovered in 330 MHz VLA observations from 2002 September 30-October 1 by Hyman et al. We have searched for bursting activity from GCRT J1745-3009 in nearly all of the available 330 MHz VLA observations of the Galactic center since 1989 as well as in 2003 GMRT observations. We report a new radio detection of the source in 330 MHz GMRT data taken on 2003 September 28. A single 0.5 Jy burst was detected, approximately 3* weaker than the five bursts detected in 2002. Due to the sparse sampling of the 2003 observation, only the decay portion of a single burst was detected. We present additional evidence indicating that this burst is an isolated one, but we cannot completely rule out additional undetected bursts that may have occured with the same 77 min. periodicity observed in 2002 or with a different periodicity. Assuming the peak emission was detected, the decay time of the burst, 2 min, is consistent with that determined for the 2002 bursts. Based on the total time for which we have observations, we estimate that the source has a duty cycle of roughly 10%.

Preprints available from the authors at shyman@sbc.edu , or the raw TeX (no figures) if you click here.

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