INTEGRAL Galactic bulge monitoring observations (see, e.g., ATels #438 and #1266) between UT 29 Aug 2010 22:54 and 30 Aug 2010 02:35 revealed X-ray flaring from the Supergiant Fast X-ray Transient (SFXT) IGR J17544-2619. Its last activity was reported about 180 days ago, in March 2010 (ATel #2463).
IGR J17544-2619 flared on time scales of about half an hour, from around a peak IBIS/ISGRI count rate of 60 +/- 10 mCrab (18-40 keV) during an 1800-sec pointing down to about 10 mCrab, i.e., near the half-an-hour detection limit. The average IBIS/ISGRI detection significance over the 12.6 ksec observation is about 19 sigma (18-40 keV). The behaviour is similar to that seen during its previous detected activity by INTEGRAL (e.g., ATel #1266, #1697).
JEM-X detects IGR J17544-2619 too, at 22 +/- 12 mCrab (3-10 keV, 3 sigma), and 40 +/- 22 mCrab (10-25 keV, 4 sigma), over the course of the observation.
Since activity at other wavelengths is expected (see, e.g., ATel #2475) we encourage follow-up observations. The next INTEGRAL Galactic bulge monitoring observation is expected to start at UT 4 Sep 2010 11:26.
The INTEGRAL Galactic bulge monitoring results (JEM-X and IBIS/ISGRI light curves and mosaic images) are publicly available at http://isdc.unige.ch/Science/BULGE/.
|Publication date||30 Aug 2010|
|Publication status||Published - 30 Aug 2010|
|Series||The Astronomer's telegram|