Swift/XRT follow-up of unidentified INTEGRAL sources (4)
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
Credential Certification: Raffaella Landi (email@example.com)
Subjects: X-ray, Gamma Ray, Request for Observations
Referred to by ATel #: 1620
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
at RA(J2000) = 17h 40m 26.62s and Dec(J2000) = -36d 55m 36.4s (4 arcsec uncertainty). This source is
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.