A magnetar-like burst from 1RXS J170849.0-400910
ATel #10107; R. F. Archibald (McGill), P. Scholz (DRAO), and V. Kaspi (McGill)
on 21 Feb 2017; 20:24 UT
Credential Certification: Robert Archibald (firstname.lastname@example.org)
Subjects: X-ray, Neutron Star, Magnetar
We report the detection of a magnetar-like burst from 1RXS J170849.0-400910 (1708). 1708 is an 11.0 s magnetar (see e.g. Dib & Kaspi 2014 and references therein) that is being monitored as part of an ongoing study of several magnetars with the Swift XRT (see Scholz et al 2014). In an XRT observation in WT mode (observation ID 00035318134) taken on MJD 57801 (17-Feb-2017), we detect a burst at MJD 57801.206136 with a false alarm probability of < 1E-6, using the mean count rate of the observation and assuming Poisson statistics. The burst has a fluence of 5 counts in a 100 ms window, compared to a mean count rate of 0.88(2) counts per second in the 1-10 keV band. We detect no change in the persistent 1-10 keV flux or pulse shape associated with this burst. This is the first reported magnetar-like burst from this source, and confirms that such bursts are generic to the source class, even when in apparent quiescence.