Swift detects an outburst from XMMU J004855.5-734946

ATel #9197; P. A. Evans (U. Leicester), J. A. Kenna (PSU), M. J. Coe (U. Southampton)
on 28 Jun 2016; 13:35 UT
Credential Certification: Phil Evans (pae9@star.le.ac.uk)

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Swift detects an outburst from XMMU J004855.5-734946

Swift has undertaken a new programme to routinely survey a region of the Small Magellanic Cloud. This programme currently consists of 143 pointings covering 13.2 square degrees, observed for 60 s each approximately once a week.

In the observation beginning at 2016 June 16 at 02:39:29 UT the catalogued source XMMU J004855.5-734946 was detected with a 0.3—10 keV count rate of 0.08±0.03 ct s^-1. This is consistent with the flux determined from the EPIC-MOS spectrum of the source in the 3XMM catalogue (6.4×10^-13 erg cm^-2 s^-1); we fitted the spectrum with an absorbed power law with N_H=1.5×10²¹ cm^-2 and Γ=0.8).

In the recent Swift observation at 2016 June 24 at 02:36:51 UT the 0.3—10 keV count rate is 0.18±0.05 ct/sec.

We therefore conclude that the source is in outburst.

This object is likely a high mass X-ray binary (Haberl & Sturm, 2016, A&A, 586, A81), in which sources outbursts are not uncommon. Due to the very short (60-s) exposure we were unable to measure the X-ray spectrum during this outburst.