1 National Space Institute, Technical University of Denmark2 Astrophysics, National Space Institute, Technical University of Denmark
A fast X-ray transient, possibly a Type-I X-ray burster has been discovered in public INTEGRAL data. The burst occurred at 07:55:33 (UTC) on March 22, 2005, and was detected in the JEM-X X-ray monitor. The position of the source, designated IGR J17464-2811, was determined in the 3-30 keV energy interval to be RA = 266.810 deg, DEC = -28.185 (J2000), with a 90% error radius of 1 arcmin. In the 3-8 keV band the burst showed a fast rise and an exponential decay with a time constant of about 70 seconds. In the 8-30 keV band the burst showed a gradual rise over 25 seconds followed by an exponential decay with a time constant of about 30 seconds, indicating a spectral softening characteristic of Type-I X-ray bursters. The burst reached a peak flux of 1.0 Crab in the JEM-X 3-30 keV band. The outburst was also clearly detected and localized with ISGRI up to 30 keV. 10 weak sources are found within the JEM-X error circle in the XMM 2XMMp and Chandra CXOGCR catalogs.