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Swift XRT confirmation of HD 306414 as the counterpart to IGR J11215-5952

ATel #768; D. Steeghs, M. A.P. Torres (CfA), P. G.Jonker (CfA/SRON)
on 21 Mar 2006; 15:33 UT
Credential Certification: Danny Steeghs (dsteeghs@cfa.harvard.edu)

Subjects: X-ray, Binary, Neutron Star, Transient

Referred to by ATel #: 773, 994

Following the report of renewed activity in the hard X-ray transient IGR J11215-5952 (ATEL #469, #766), we have obtained a Swift TOO observation of the field covering this X-ray source.

An X-ray Telescope (XRT) observation was obtained during 2006 March 20 18:50-19:02UT in Photon Counting mode with 640s on source. A single faint X-ray source was detected in the field of view with a mean event-rate of 0.05 counts/sec. Its position was determined to be R.A.(J2000): 11:21:46.9, Dec(J2000): -59:51:42 with an estimated error radius of 5 arcseconds. This position is within the 1.2 arcmin INTEGRAL position reported in Sidoli, Paizis & Mereghetti (astro-ph/0603081). The ROSAT archive lists no strong sources within this field of view, and we conclude that the detected XRT source is thus associated with IGR J11215-5952. The XRT position is consistent with the bright supergiant HD306414 and therefore confirms the association proposed by Negueruela, Smith & Chaty (ATEL#470).

For a range of spectral models, we derive an observed 2-10 keV flux close to ~1e-11 ergs/cm2/s. This is significantly below the peak flux reported in ATEL #766 though still well above the expected quiescent luminosity.

We thank the Swift team, in particular Jamie Kennea, for making this observation possible.