INTEGRAL Bulge monitoring program detects several active transients with JEM-X

J. Chenevez*, E. Kuulkers, J. Alfonso-Garzón, V. Beckmann, T. Bird, S. Brandt, M. Del Santo, A. Domingo, K. Ebisawa, P. Jonker, P. Kretschmar, C. Markwardt, T. Oosterbroek, A. Paizis , K. Pottschmidt, C. Sánchez-Fernández , R. Eijnands

*Corresponding author for this work

Research output: Other contributionNet publication - Internet publicationResearch


A new season of the INTEGRAL Galactic bulge monitoring program (see ATel #438) has begun with an observation of seven pointings obtained between 2012 Feb 14.375 (9 UT) and 14.528 (12:41 UT), and reveals several transient X-ray sources detected by the twin JEM-X instruments. For temporary technical reasons the IBIS instrument was not taking data during these pointings.

We find the low-mass X-ray binary SAX J1747.0-2853 at a flux of 245 +/-65 mCrab between 3-10 keV with a detection significance of 4 sigma for a total effective exposure of 14.9 ksec. The source is not detected in the 10-25 keV band with an upper limit of 5 mCrab. The last outburst of this transient source was observed a year ago, lasting from end of January until at least end of March 2011 (see, e.g., ATels #3123, #3172, #3183, #3217).

The black hole candidate and microquasar H1743-322 (also known as IGR J17464-3213), observed during a total effective exposure of 7.5 ksec, is measured at a flux of 350 +/- 100 mCrab with a detection significance of 3.5 sigma between 3-10 keV, and 53 +/-25 mCrab at 2.5 sigma between 10-25 keV. The source was observed by INTEGRAL at the beginning of an outburst in April 2011 (ATels #3263, 3267), and renewed activity was reported by MAXI at the end of 2011 (ATel #3842).

The X-ray burster KS 1741-293 (AX J1744.8-2921) is clearly active at a measured flux of 415 +/- 75 mCrab between 3-10 keV for a detection significance of 5.5 sigma and effective exposure of 15 ksec, and 80 +/- 10 mCrab at 9 sigma between 10-25 keV. A short (15 sec) X-ray burst is detected with a 3-25 keV peak flux of 0.6 Crab at UT 10:46:39 on February 14th.

INTEGRAL will continue to monitor the Galactic bulge about every third day until mid April, and observation results from near real time data will be made available at:
Original languageEnglish
Publication date16 Feb 2012
Publication statusPublished - 16 Feb 2012
SeriesThe Astronomer's telegram
NumberATel #3930


  • X-ray
  • Black hole
  • Neutron star
  • Transient


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