GRO J1744-28: search for radio counterpart with the GMRT
ATel #5904; M. Pandey-Pommier (CRAL-l'Observatoire de Lyon-France), N. Masetti (INAF/IASF, Bologna- Italy), P. Durouchoux (ECE, Paris- France)
on 19 Feb 2014; 08:48 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Mamta Pandey-Pommier (mamtapan@gmail.com)
Subjects: Radio, Binary, Neutron Star, Transient, Variables
Referred to by ATel #: 5997
As a part of radio follow-up observation program on X-ray transients in low-mass X-ray binaries, we obtained a short GMRT observation on the rare bursting accretion-powered pulsar GRO J1744-28 during its recent outburst (ATel #5790, #5810, #5845, #5858, #5883, #5896, #5901). Our observation was made on 2014 February 12 in continuum mode for 2 hours.
No possible radio counterpart was detected at 610 MHz for GRO J1744-28 with the GMRT up to 0.5+/-0.1 mJy level within the Chandra position error circle (ATel #5895).
It is interesting to note that there is an unresolved background source, GMRT 1744-28 at a flux level of 2.5+/-0.01 mJy, present within the field. Its best-fit position is:
RA(J2000) = 17h 44m 31.09s
Dec(J2000) = -28d 44' 26.8"
with an uncertainty radius of 5 arcsec (90% confidence) at 610 MHz. This is the only unresolved radio source present in the RXTE position error uncertainty radius (1.5 arcmin) (Smith. et al. 1997). This radio source is 30 arcsec away from SWIFT/XRT (ATel #5845) and Chandra counterparts (Wijnands and Wang 2002, ApJ, 568, L93).
There is no radio data available in the NVSS, FIRST archive for comparison. Simbad database shows no known radio source within 30 arcsec of the above mentioned radio source.
As the GMRT radio source is not coincident at 3-sigma level with the Swift/XRT and Chandra positions for GRO J1744-28 (ATels #5845, #5895), we suggest that this radio source is most likely not associated with GRO J1744-28.
We thank the staff of the GMRT who have made these observations possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research.