New X-ray transient IGR J11435-6109 discovered with INTEGRAL
ATel #350; S. A.Grebenev (IKI, Moscow), P. Ubertini (IASF, Roma), J. Chenevez (DSRI, Kopenhagen), N. Mowlavi (ISDC, Versoix), J.-P. Roques (CESR, Toulouse), N. Gehrels (NASA/GSFC, Greenbelt), E. Kuulkers (ESTEC, Noordwijk)
on 29 Nov 2004; 16:06 UT
Distributed as an Instant Email Notice Request For Observations
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Subjects: Radio, Infra-Red, Optical, X-ray, Request for Observations, Binary, Black Hole, Neutron Star, Transient
A new hard X-ray transient, IGR J11435-6109, was discovered with the IBIS/ISGRI telescope on board INTEGRAL on Nov. 23, 2004, during observations (3 successive pointings at 12:30-14:20 UTC) dedicated to the Galactic Plane Scan. The source was located 1 deg off the known X-ray pulsar twins, 4U1145-619 and 1E1145.1-6141, at the position, R.A.= 11h43m52s, Dec.= -61d09m00s (equinox 2000.0, error radius 2.5'), generally consistent with that of the faint ROSAT source 1RXS J114358.1-610736. The S/N ratio was 9.5 in the 18-45 keV mosaic image, the corresponding average flux was equal to 18+/-2 mCrab.
The source was also detected in the standard X-ray band with the JEM-X telescope during one of the pointings. This detection as well as the possible association of IGR J11435-6109 with 1RXS J114358.1-610736 let us to suggest that it differs from the main population of (strongly photoabsorbed) new INTEGRAL sources.
We encourage follow-up observations of this source at all wavelengths.