Swift XRT Observation of the Magnetar 4U 0142+61 Following a Burst
ATel #10576; R. F. Archibald (McGill), V. M. Kaspi (McGill), P. Scholz (DRAO),and S. P. Tendulkar (McGill)
on 16 Jul 2017; 22:19 UT
Credential Certification: Robert Archibald (firstname.lastname@example.org)
Subjects: X-ray, Neutron Star, Pulsar, Magnetar
We report on Swift X-ray Telescope (XRT) observations made following an X-ray/soft gamma-ray burst detected by Fermi-GBM and Swift BAT on 14 July 2017 (GCN 21342) from the direction of the magnetar 4U 0142+61. We observed the source on 15 July 2017 (MJD 57949.8) for 2.9 ks with the Swift XRT in windowed timing mode. We detect a modest change in the X-ray flux relative to pre-burst epochs: we measure an absorbed phase-average 0.5-10 keV flux of 1.51(3)E-10 ergs/s/cm^2 for the 15 July 2017 observation, compared with 1.35(3)E-10 ergs/s/cm^2 for the prior observation on 3 July, 2017 (MJD 57937.1). We detect no evidence for a glitch associated with this burst, with the pulse time-of-arrival measured for the latest observation being 0.02(1) phase-turns from the pre-burst timing model. The pulse shape is also consistent with being unchanged. We detect no further bursts in the XRT data. We thank the Swift team for a rapid response to our ToO request.