The radio counterpart of the neutron star X-ray binary Swift J1922.7-1716 detected with MeerKAT
ATel #16523; M. C. Baglio, S. Motta, I. Mariani (INAF-OAB), R. Fender (Oxford University), T. D. Russell (INAF-IASF Palermo) for the X-KAT collaboration
on 12 Mar 2024; 14:45 UT
Credential Certification: Maria Cristina Baglio (cristina.baglio@brera.inaf.it)
Subjects: Radio, Binary, Neutron Star, Transient
The transient neutron star X-ray binary Swift J1922.7-1716 is currently undergoing a new outburst, as detected by MAXI on 2024 Feb 10 (ATel #16451). The outburst was also confirmed at optical frequencies thanks to the monitoring with the Las Cumbres Observatory (LCO) network of telescopes and the Robotic Eye Mount (REM) telescope (Atel #16461). No near-infrared counterpart was identified, possibly due to the high airmass conditions of the observations (Atel #16461).
After the start of the new outburst was detected, we initiated follow-up radio observations using the MeerKAT radio telescope under the X-KAT program. The first observations took place on February 19, 2024 and lasted for 15 minutes, starting on 2024-02-19 04:41:56 UT. The observations were conducted at a central frequency of 1.28 GHz (L-band), with a total bandwidth of 0.85 GHz. J1939-6342 was used for flux and bandpass calibration, J1923-2104 for phase calibration.
We detected a radio source at the following position: R.A.= 19:22:40.98 +/- 0.05, Dec= -17:21:53.75+/-0.53 (consistent with the known position of the source reported in Degenaar et al. 2012), measuring a flux density of 80 +/- 20 μJy (statistical error).
We will continue monitoring Swift J1922.7-1716 with the MeerKAT radio telescope. Multi-wavelength observations are encouraged.
X-KAT is a large MeerKAT open-time programme to observe X-ray binaries in the radio band, performing weekly monitoring of bright, active systems, with capacity for higher cadence observations, and in coordination with large X-ray and optical monitoring programmes. For further information on this programme contact Rob Fender. The Swift follow-up of X-ray binaries is largely performed as part of the SwiftKAT program, which provides quasi simultaneous X-ray coverage of the X-KAT targets.
