MeerKAT radio non-detection of the accreting millisecond X-ray pulsar MAXI J1957+032
ATel #15462; Jakob van den Eijnden, Rob Fender (University of Oxford), Patrick Woudt (University of Cape Town), James Miller-Jones (Curtin University), Sara Motta (INAF/OAB), on behalf of the ThunderKAT collaboration
on 23 Jun 2022; 18:39 UT
Credential Certification: Jakob Van den Eijnden (a.j.vandeneijnden@uva.nl)
Subjects: Radio, Neutron Star, Transient
Referred to by ATel #: 15466
On 18 June 2022, MAXI reported activity from the faint X-ray transient MAXI J1957+032 (ATel #15440). Follow-up NICER observations then found 314 Hz pulsations, confirming the source's nature as an accreting millisecond X-ray pulsar (ATel #15444). Between 19 and 21 June 2022, NICER observed a rapid decline of the outburst (ATel #15456) , which was confirmed by observations with the Neil Gehrels Swift Observatory on 22 June (ATel #15457).
We targeted MAXI J1957+032 during this brief outburst with MeerKAT as part of the ThunderKAT Large Survey Programme (Fender et al. 2017, arXiv:1711.04132). The observation was performed on 21 June 2022 at 22:45 UTC for 15 minutes, at a central frequency of 1.28 GHz with 860 MHz of bandwidth. We do not detect any significant radio emission at the source position at an RMS sensitivity of 16 μJy/beam. Therefore, we set a 3-sigma upper limit on the flux density of 48 μJy.
ThunderKAT will run for 5 years and targets X-ray binaries, Cataclysmic Variables, Supernovae and Gamma-Ray Bursts. As part of this programme, we perform weekly monitoring observations of all bright, active, southern hemisphere X-ray binaries in the radio band. For further information on this programme please contact Rob Fender and/or Patrick Woudt.
We thank the staff at the South African Radio Astronomy Observatory (SARAO) for their rapid scheduling of these observations. The MeerKAT telescope is operated by SARAO, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.
