Swift localization of the new hard X-ray transient IGR J17498-2921

ATel #3555; E. Bozzo, C. Ferrigno, (ISDC, Switzerland), A. Papitto (Univ. Cagliary, Italy), L. Gibaud (ISDC, Switzerland)
on 13 Aug 2011; 10:50 UT
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Credential Certification: E. Bozzo (enrico.bozzo@unige.ch)

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Following the discovery of the new INTEGRAL hard X-ray transient, IGR J17498-2921 (Atel #3551), a follow-up observation of 5 ks with the narrow field instrument on-board Swift was performed in PC mode starting from 2011-08-12 at 15:41 (UTC).

A single bright source is detected within the INTEGRAL error circle. The pile-up corrected spectrum could be well fit with a simple absorbed power-law model. We estimated an absorption column density of (3.0+/-0.3)E22 cm^(-2) and a photon index of 1.9+/-0.2 (in agreement with the photon index determined from IBIS/ISGRI, Atel #3551; uncertainties are at 90% c.l.). The corresponding flux is 2e-10 ergs/cm^2/s (2-10 keV, not corrected for absorption).

We obtained a preliminary source position at: RA = 267.4819 Dec = -29.3227 (J2000) with an associated 90% c.l. uncertainty of 4 arc seconds obtained using the xrtcentroid tool. However, due to the pile-up that affected the observation, we estimated the confinement radius by connecting the spikes of the images. This method suggests an increased uncertainty radius of 7 arcsec.

A more refined analysis is ongoing. Further observations of the source with Swift are already requested.

We thank the Swift Team for the very rapid scheduling of the observation of IGRJ17498-2921