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ATEL # 1539; R. Landi, N. Masetti, A. Malizia (INAF/IASF Bologna), M. Del Santo, A. Tarana (IASF/INAF Roma), A.J. Bird, A.J. Dean (Univ. Southampton), P. Caraveo, F. Senziani (INAF/IASF Milano)
on 20 May 2008; 14:40 UT
Password Certification: Raffaella Landi (firstname.lastname@example.org)
Subjects: X-ray, Gamma Ray, Request for Observations
We report the results of a series of X-ray follow-up observations performed with Swift/XRT of three unidentified INTEGRAL sources belonging to the 3rd IBIS Survey Catalogue (Bird et al. 2007, ApJS, 170, 175).
Within the IBIS uncertainty XRT detects an X-ray source, with a statistical significance of 12 sigma, located at RA(J2000) = 13h 18m 25.61s and Dec(J2000) = -62d 58m 15.0s (4.1 arcsec uncertainty). There are two USNO-B1.0 sources within the XRT error box and three objects belonging to the 2MASS survey. The X-ray data are well described by an unabsorbed flat (Gamma ~0.17) power law with a 2-10 keV flux of 5.8 x 10-11 erg cm-2 s-1.
Within the IBIS error box of this source we find an X-ray emitter, with a statistical significance of 6.7 signa, located at RA(J2000) = 15h 52m 46.56s and Dec(J2000) = -50d 29m 52.3s (4.9 arcsec uncertainty). Within the XRT uncertainty there are two 2MASS objects of which only one has a counterpart in the USNO-B1.0 catalogue. The X-ray spectrum is fitted with an unabsorbed flat (Gamma ~0.9) power law having a 2-10 keV flux of 1.7 x 10-12 erg cm-2 s-1.
There is an X-ray source, with a statistical significance of 12 sigma, within the IBIS error circle located at RA(J2000) = 17h 40m 26.62s and Dec(J2000) = -36d 55m 36.4s (4 arcsec uncertainty). This source is likely associated with a ROSAT Faint object (1RXS J174024.4-365540). Within the XRT positional uncertainty, we find a USNO-B1.0 object having magnitude R ~16.8-17.8 also listed in the 2MASS catalogue. The X-ray spectroscopy indicates an unabsorbed flat (Gamma ~0.24) spectrum providing a 2-10 keV flux of 1.2 x 10-11 erg cm-2 s-1.