Journal or Book Title
The Astrophysical Journal
We present new X-ray timing and spectral observations of PSR J1930+1852, the young energetic pulsar at the center of the nonthermal supernova remnant G54.1+0.3. Using data obtained with the Rossi X-Ray Timing Explorer (RXTE) and Chandra X-ray observatories we have derived an updated timing ephemeris of the 136 ms pulsar spanning 6 years. During this interval, however, the period evolution shows significant variability from the best-fit constant spin-down rate of = 7.5112(6) × 10-13 s s-1, suggesting strong timing noise and/or glitch activity. The X-ray emission is highly pulsed (71% ± 5% modulation) and is characterized by an asymmetric, broad profile (~70% duty cycle) that is nearly twice the radio width. The spectrum of the pulsed emission is well fitted with an absorbed power law of photon index Γ = 1.2 ± 0.2; this is marginally harder than that of the unpulsed component. The total 2-10 keV flux of the pulsar is 1.7 × 10-12 ergs cm-2 s-1. These results confirm PSR J1930+1852 as a typical Crab-like pulsar.
Lu, F; Wang, QD; Gotthelf, EV; and Qu, J, "X-Ray Timing Observations of PSR J1930+1852 in the Crab-like SNR G54.1+0.3" (2007). The Astrophysical Journal. 1065.