Glitch observation and hard X-ray power law measurement in PSR J1119-6127
ATel #9284; R. F. Archibald (McGill), S. P. Tendulkar (McGill), P. A. Scholz (McGill), and V. M. Kaspi (McGill)
on 31 Jul 2016; 04:09 UT
Credential Certification: Shriharsh Tendulkar (shriharsh@physics.mcgill.ca)
Subjects: X-ray, Gamma Ray, Soft Gamma-ray Repeater, Pulsar
We report on Swift-XRT, NuSTAR and Fermi spectral and timing observations of PSR J1119-6127, a rotation-powered high magnetic field pulsar that showed a magnetar-like burst on 2016 July 28, 01:27:51 UT (ATel #9274, ATel #9282).
We extend the pre-burst timing solution presented in Antonopoulou et al. 2015 using Fermi-LAT data and compare it to the spin frequency detected in the Swift-XRT observation on MJD 57597-57598 (Obsid 00034632001). The measured spin frequency is higher than predicted value by 1.42(5)E-5 Hz. This implies that a large spin-up glitch occurred accompanying the hard X-ray detected bursts. Further observations are encouraged to monitor the evolution of this large glitch.
NuSTAR began Target of Opportunity (ToO) observations of PSR J1119-6127 at 2016 July 28, 23:05:12 UT with a total exposure time of 54.5 ks. The NuSTAR observations partially overlapped with the Swift-XRT ToO observations that ended at 2016 July 29 03:11:11 UT. We find that the Swift-XRT and NuSTAR spectra are well-fit by an absorbed blackbody plus power law model (red. chisq/dof = 1.0243/456). The measured blackbody temperature is kT = 0.96(1) keV and the power law photon index is Gamma = 1.5(2). The unabsorbed 3-79 keV flux is 1.81E-11 erg/cm^2/s. We find that the spectra are not well-fit by a single absorbed power law model (as suggested in ATel #9282) or a single absorbed blackbody model. The measured photoelectric absorption column density, nH is 1.2(2)E22 /cm^2 (with 'wilm' abundances and 'vern' photoelectric cross-sections).
We thank the NuSTAR Science Operations team for rapidly scheduling the observation and providing data products.