Improved Swift-XRT position of the transient source in Terzan 5
ATel #3723; P. A. Evans, A. P. Beardmore, J. P. Osborne (U. Leicester), J. A. Kennea (PSU)
on 28 Oct 2011; 17:05 UT
Credential Certification: Phil Evans (pae9@star.le.ac.uk)
Subjects: X-ray, Binary, Globular Cluster, Neutron Star, Transient
Referred to by ATel #: 3743
We have analysed the Swift-XRT observations of the transient object in Terzan 5 reported in ATEL #3720 (obsID 00032148001), using the online Swift "User Object" tools (http://www.swift.ac.uk/user_objects). These tools account for pile-up in the source localisation process by using PSF profiles appropriate for piled-up sources: details are given in Evans et al. (2009, MNRAS, 397, 1177).
The enhanced XRT position, which uses field stars in the UVOT to determine the spacecraft attitude (see Goad et al. 2007, A&A, 476, 1401) is: (J2000) 17:48:5.20, -24:46:48.7, with an uncertainty of 2.1 arcsec (radius, 90% confidence).
This improved position lies 5 arcsec from the X-ray pulsar IGR J17480-2446, and 1.4 arcsec from EXO 1745-248, making the tentative association in ATEL #3720 of the new transient with the latter object more probable.
