MeerKAT observes no radio emission from the X-ray transient MAXI J1810-222
ATel #12521; Francesco Carotenuto, Evangelia Tremou, Stephane Corbel (CEA-Saclay), Rob Fender (Oxford, UCT), Patrick Woudt (UCT), James Miller-Jones (Curtin), on behalf of the ThunderKAT collaboration
on 20 Feb 2019; 16:32 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Evangelia Tremou (evangelia.tremou@cea.fr)
Subjects: Radio, Binary, Transient
The soft X-ray transient MAXI J1810-222 was detected by MAXI/GSC on 2018-12-01 (MJD 58453) (ATels #12254, #12264) and was then observed by NuSTAR (ATels #12283, #12398) and by Swift/XRT (ATel #12487). ATel #12496 from MAXI/GSC on 2019-02-11 (MJD 58525) reports a re-brightening of the source, with a 2-4 keV flux of ~40 mCrab. A possible optical GAIA counterpart suggests a distance of ~730 pc, but the nature of the source is still unknown.
As part of the ThunderKAT Large Survey Programme (Fender et al., 2017), we conducted radio observations with the new MeerKAT radio telescope located in the Karoo desert in South Africa.
We observed for 15 minutes on 2019-02-16 (MJD 58530.16) from 03:56 UT to 04:11 UT with 59 antennas, at a central frequency of 1.284 GHz, with a total bandwidth of 860 MHz.
The observation resulted in a non-detection at the X-ray position of the source (ATel #12487) with an image RMS noise level of 33 uJy/beam, therefore we place a 3-sigma upper limit of 99 uJy/beam at the location of the transient.
Further follow-up observations are encouraged to reveal the nature of this soft X-ray source.
ThunderKAT will run for 5 years and aims to monitor 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 scheduling 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 Technology.