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 ± 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
http://isdc.unige.ch/Science/BULGE
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.
