MeerKAT observations of the AMXP SAX J1808.4-3658
ATel #12982; David Williams, Sara Motta (Oxford), Rob Fender (Oxford, UCT), Patrick Woudt (UCT), James Miller-Jones (Curtin) on behalf of the ThunderKAT collaboration
on 2 Aug 2019; 14:24 UT
Credential Certification: Sara Elisa Motta (sara.motta@physics.ox.ac.uk)
Subjects: Radio, Binary, Neutron Star, Transient
Referred to by ATel #: 13026
The accreting millisecond X-ray pulsar SAX J1808.4-3658 was reported (ATel #12964) to be brightening in the optical i'-band from the 25th - 30th July. As part of the ThunderKAT Large Survey Programme (http://adsabs.harvard.edu/abs/2017arXiv171104132F ), we observed the field of SAX J1808.4-3658 on 2019-07-31 for 15 minutes at 1.28GHz, starting our observation at 17:43:49.0 UTC. We used standard reduction techniques, using PKS J1939-6342 as the primary flux and band pass calibrator and NVSS J183058-360231 as the phase calibrator.
We do not detect any radio emission coincident with the position of SAX J1808.4-3658, at the phase centre of the image. The rms noise level at the phase centre is ~36 uJy/beam, allowing us to place a 3 sigma upper limit for SAX J1808.4-3658 of 110uJy/beam. We will continue to monitor this source as part of the ThunderKAT monitoring programme.
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 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 Technology.
