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

ATel #3930; J. Chenevez (DTU Space, Denmark), E. Kuulkers (ESA/ESAC, Spain), J. Alfonso-Garzón (CAB/INTA-CSIC, Spain), V. Beckmann (APC, France), T. Bird (Southampton, UK), S. Brandt (DTU Space, Denmark), M. Del Santo (INAF/IASF-Roma, Italy), A. Domingo (CAB/INTA-CSIC, Spain), K. Ebisawa (ISAS, Japan), P. Jonker (SRON, The Netherlands), P. Kretschmar (ESA/ESAC, Spain), C. Markwardt (GSFC, USA), T. Oosterbroek (ESA/ESTEC, The Netherlands), A. Paizis (INAF-IASF, Italy), K. Pottschmidt (UMBC/NASA GSFC, USA), C. Sánchez-Fernández (ESA/ESAC, Spain), R. Wijnands (UvA, The Netherlands)
on 16 Feb 2012; 16:54 UT
Credential Certification: Jerome CHENEVEZ (jerome@space.dtu.dk)

Subjects: X-ray, Black Hole, Neutron Star, Transient

Referred to by ATel #: 5041, 6602

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: http://integral.esac.esa.int/BULGE/index.html