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ATEL # 1489; A. Carmona (ISDC, Switzerland), V. Beckmann (ISDC), J. Rodriguez (CEA/SAp & AIM, Saclay, France)
on 25 Apr 2008; 16:57 UT
Distributed as an Instant Email Notice (Request for Observations)
Password Certification: Volker Beckmann (Volker.Beckmann@obs.unige.ch)
Subjects: Request for Observations, Transients
During an INTEGRAL observation of GRS 1915+105, the IBIS/ISGRI telescope detected a new hard X-ray transient, IGR J19112+1358, at the position RA = 19 11 12.6, DEC= +13 58 52 (statistical error of 4'). The source is detected in the combined data set at 6 sigma in the 20-40 keV band with a rate of 1.2+-0.2 cps (about 7 mCrab) for an effective exposure time of 13.4 ksec, starting at 2008-04-24T07:05. IGR J19112+1358 is neither detected at a single pointing level (2ksec), nor in the IBIS/ISGRI mosaic image in the 40-80 keV band. IGR J19112+1358 has been in the IBIS/ISGRI field of view also prior to this observation but was not detected. The last observation on 2008-04-17 gives a 3 sigma upper limit of about 4 mCrab. The source is not visible in the JEM-X1 data (3-20 keV).
The IBIS/ISGRI spectrum can be represented by a single power law model with photon index 3.2+-0.8 and a model flux of 5e-11 erg/cm**2/sec (20-40 keV).
We remark that within the ISGRI error box lies the infrared source IRAS 19089+1351 at 2.6 arcmin distance to IGR J19112+1358. We encourage observations at other wavelength, while we will continue to monitor this field with INTEGRAL.