INTEGRAL detects hard X-ray emission from XTE J1817-330
ATel #731; S. E. Shaw (Southampton, UK/ ISDC, Geneva); J. Zurita (ISDC, Geneva); E. Kuulkers (ESA/ESAC, Spain); S. Brandt, J. Chenevez (DNSC, Denmark); T. J.-L. Courvoisier (ISDC, Geneva); K. Ebisawa (NASA/GSFC, USA); P. Kretschmar (ESA/ESAC, Spain); C. Markwardt (NASA/GSFC, USA); N. Mowlavi (ISDC, Geneva); T. Oosterbroek (ESA/ESTEC, Netherlands); A. Orr (ESA/ESTEC, Netherlands); A. Paizis (IASF, Milano); C. Sanchez-Fernandez (ESA/ESAC, Spain); R. Wijnands (UvA, Netherlands)
on 10 Feb 2006; 10:38 UT
Credential Certification: Nami Mowlavi (Nami.Mowlavi@obs.unige.ch)
Subjects: X-ray, Gamma Ray, Black Hole, Transient
During the start of the third period of the INTEGRAL Galactic Bulge monitoring observations (Kuulkers et al 2005, ATel #438), the X-ray transient and black-hole candidate XTE J1817-330 (ATel #714) has been detected in the 20 - 150 keV range. The observations comprised ~7 ksec taken on 9 Feb 2006 between 09:02 and 11:43 UTC.
The estimated flux seen by ISGRI in the 20-60 keV range was ~33 mCrab, which compares with an earlier measurement, on 27 Jan 2006, of 22 mCrab in the 10-30 keV band (ATel #714). There is also evidence of emission at higher energies, with an average flux in the 60-150 keV band of 1.9 Â± 0.4 cps (~ 44 mCrab). Spectral analysis indicates a hard spectrum with a power-law photon index of 1.6 +/- 0.3.
Unfortunately, the source was outside of the field of view of the JEM-X instrument and so no comment can be made on the sources's behaviour below 15 keV.
Images and light curves from the observations are available at
The source will again be observed by INTEGRAL in the next Galactic Bulge pointing on 11-12 Feb 2006. A longer (195 ksec) INTEGRAL TOO observation is foreseen on 15-18 Feb, 2006.
Simultaneous observations are encouraged.