Following the detection of high energy emission from Swift J1749.4-2807 by INTEGRAL between April 10 and 11, 2010 (ATel #2548) a new INTEGRAL observation of the Galactic bulge (see ATel #438) took place on April 13 between 15:00 and 18:42 (UTC) during which persistent emission from this source was again recorded.
The JEM-X monitor measured the average persistent emission from the source during the 8 ks total exposure to be 12 +/-3 mCrab and 18 +/- 6 mCrab in the energy bands between 3-10 keV and 10-25 keV, respectively.
A type I X-ray burst from Swift J1749.4-2807 was detected on April 13, 2010 at 16:51 (UTC) lasting about 15 s with a peak flux of about 1 Crab and an exponential decay of 13 s in the 3-25 keV band. This is to our knowledge the second burst ever recorded from this source (see Wijnands et al. 2009, MNRAS 393, 126).
We derive an unabsorbed bolometric peak burst flux of 3e-8 erg/cm2/s, and assuming this corresponds at most to the Eddington luminosity (see Kuulkers et al. 2003, A&A 399, 663) we derive an upper limit of the distance to the source of 10 kpc.
A last INTEGRAL observation of the Galactic bulge is scheduled for April 21 before the region becomes unobservable due to solar constraints.
|Publication date||14 Apr 2010|
|Publication status||Published - 14 Apr 2010|
|Series||The Astronomer's telegram|