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Swift follow-up of the renewed activity of IGR J19294+1816

ATel #4136; L. Sidoli (INAF-IASF, Milano), S. P. Drave (Southampton, UK), M. Fiocchi, A. Bazzano (INAF-IAPS, Roma, Italy), V. Sguera (INAF-IASF, Bologna, Italy), J. Chenevez (DTU Space, Denmark), A. J. Bird (Southampton, UK), E. Kuulkers (ESA/ESAC, Spain), L. Natalucci, A. Tarana (INAF-IAPS, Roma, Italy)
on 30 May 2012; 11:17 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Lara Sidoli (sidoli@lambrate.inaf.it)

Subjects: X-ray, Gamma Ray, Binary, Neutron Star, Transient, Pulsar

Referred to by ATel #: 5104

Following the renewed activity of the X-ray transient pulsar IGRJ19294+1816 observed by INTEGRAL (ATel #4135), Swift pointed at the source position for about 2 ks starting on 2012 May 28 at 17:45:15 UT. The source displayed a net count rate of 0.18 +/- 0.01 c/s (2-10 keV, XRT PC data).

The XRT spectrum (PC data, net exposure time of 1968 s) is well described by an absorbed power law model, resulting in a photon index of 1.25 (+0.77,-0.68), and in an absorption of NH= 8 (+/-4) E+22 cm-2 (chi2_red=0.600 for 11 dof). The source fluxes are 3E-11 erg/cm2/s (1-10 keV, observed) and 5E-11 erg/cm2/s (1-10 keV, unabsorbed), indicating a declining phase with respect to the INTEGRAL observation. A black body model results in an equally good fit to the data, with NH= 4 (+/-3) E+22 cm-2 and a temperature of 2.0 (+0.7,-0.4) keV (chi2_red=0.633 for 11 dof).

A timing analysis on the barycentered events clearly shows X-ray pulsations with a period of P=12.457 +/- 0.006 s and a pulse fraction of about 60%.

We would like to thank the Swift Team for making these observations possible.