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Swift/XRT Detection of the Hard X-ray Sources IGR J18244-5622 and IGR J21178+5139

ATel #945; R. Landi, N. Masetti (IASF/INAF Bologna), N. Gehrels, J. Tueller (NASA/GSFC), N. Gehrels, J. Tueller ( NASA/GSFC), C. Markwardt (UMD/NASA/GSFC), J. Kennea (PSU), P. Ubertini (IASF/INAF Rome), A. J. Bird (Univ. Southampton) and F. Lebrun (APC/CEA-Saclay)
on 16 Nov 2006; 15:41 UT
Credential Certification: Raffaella Landi (landi@iasfbo.inaf.it)

Subjects: X-ray, Gamma Ray, AGN, Star

Two INTEGRAL sources, IGR J18244-5622 and IGR J21178+5139, have recently been observed and detected with the Swift/XRT X-ray telescope.

In the following we report the results of these measurements:

IGR J18244-5622
The XRT observation locates the source at RA = 18 24 19.49, Dec = -56 22 08.72 [J2000] with an error of 4.4", thus confirming a previous association with the Sey2 galaxy IC 4709 at z=0.017 (see Masetti et al. 2006, A&A 459, 21 for the optical spectroscopy); the X-ray spectroscopy indicates an absorbed power law spectrum (Gamma=1.9 and NH = 14 x 10^22 cm-2) compatible with the AGN type II class.

IGR J21178+5139
The XRT observation locates the source at RA = 21 17 47.24, Dec = +51 38 53.62 [J2000] with an error of 10" (with the big uncertainty due to the location of the source right on the edge of the XRT field of view) and allows the identification of the ISGRI object with a radio/infrared source (2MASX J21174741+5138523/NVSS J211747+513855) having a 20cm flux of about 9 mJy and magnitude R~13; the XRT position is also compatible with a source in the Rosat Faint Source Catalogue (1RXS J211746.9+513901). There is no optical counterpart within the XRT error box down to the DSS-1 survey limit (R>21) implying a heavily absorbed object (R-K>8).The X-ray spectroscopy confirms the presence of intrinsic absorption (NH = 13 x 10^22 cm-2 for Gamma=1.8).