Detection of the NIR counterpart of the accreting millisecond pulsar IGR J17591-2342
ATel #11970; A. W. Shaw (University of Alberta), N. Degenaar (Univeristy of Amsterdam), C. O. Heinke (University of Alberta)
on 19 Aug 2018; 19:14 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Aarran Shaw (aarran@ualberta.ca)
Subjects: Infra-Red, Neutron Star, Transient, Pulsar
Referred to by ATel #: 12004
We report on near-infrared (NIR) follow-up of the new accreting millisecond X-ray pulsar IGR J17591-2342, discovered by INTEGRAL and localized by Swift and ATCA (ATel #11941, #11942, #11954).
We obtained imaging in the Ks and H bands, using the High Acuity Wide-field K-Band Imager (HAWK-I) mounted on UT4 of the Very Large Telescope on Cerro Paranal, Chile. Conditions were excellent, with seeing <1". We obtained 7 exposures of 195s in Ks, with each co-added exposure consisting of 13 dithered 15s exposures. In H we obtained 7 exposures of 65s, with each co-add consisting of 13 dithered 5s exposures. Data were reduced with ESO's reflex pipeline and we extract photometry from the pipeline products.
We detect a source at RA (J2000) =17:59:02.87, Dec (J2000) = -23:43:08.2, with magnitudes of H=19.56 +/- 0.07 and Ks=18.37 +/- 0.07. The source position is completely consistent with the ATCA position reported by Russell et. al. (ATel #11954) and the typical astrometric uncertainty in the HAWK-I images is ~0.03". We therefore propose that this is the NIR counterpart of the pulsar.
Though the counterpart is faint, follow-up observations are encouraged, particularly NIR spectroscopy.
