@article {41764,
	title = {Timing Six Energetic Rotation-powered X-Ray Pulsars, Including the Fast-spinning Young PSR J0058-7218 and Big Glitcher PSR J0537-6910},
	volume = {939},
	year = {2022},
	month = {2022/11/1},
	pages = {7},
	publisher = {IOP},
	abstract = {Measuring a pulsar{\textquoteright}s rotational evolution is crucial to understanding the nature of the pulsar. Here, we provide updated timing models for the rotational evolution of six pulsars, five of which are rotation phase-connected using primarily NICER X-ray data. For the newly discovered fast energetic young pulsar, PSR J0058-7218, we increase the baseline of its timing model from 1.4 days to 8 months and not only measure more precisely its spin-down rate $\dot{\nu }=(-6.2324\pm 0.0001)\times {10}^{-11}\,\mathrm{Hz}\,{{\rm{s}}}^{-1}$ but also for the first time the second time derivative of its spin rate $\ddot{\nu }=(4.2\pm 0.2)\times {10}^{-21}\,\mathrm{Hz}\,{{\rm{s}}}^{-2}$ . For the fastest and most energetic young pulsar, PSR J0537-6910 (with a 16 ms spin period), we detect four more glitches, for a total of 15 glitches over 4.5 yr of NICER monitoring, and show that its spin-down behavior continues to set this pulsar apart from all others, including a long-term braking index n = -1.234 {\textpm} 0.009 and interglitch braking indices that asymptote to ≲7 for long times after a glitch. For PSR J1101-6101, we measure a much more accurate spin-down rate that agrees with a previous value measured without phase connection. For PSR J1412+7922 (also known as Calvera), we extend the baseline of its timing model from our previous 1 yr model to 4.4 yr, and for PSR J1849-0001, we extend the baseline from 1.5 to 4.7 yr. We also present a long-term timing model of the energetic pulsar PSR J1813-1749, by fitting previous radio and X-ray spin frequencies from 2009-2019 and new ones measured here using 2018 NuSTAR and 2021 Chandra data.},
	keywords = {1108, 1306, 1408, 1822, 464, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, Ephemerides, Neutron stars, Pulsars, Rotation powered pulsars, X-ray sources},
	isbn = {0004-637X},
	url = {https://ui.adsabs.harvard.edu/abs/2022ApJ...939....7H},
	author = {Ho, Wynn C. G. and Kuiper, Lucien and Espinoza, Crist{\'o}bal M. and Guillot, Sebastien and Ray, Paul S. and Smith, D. A. and Bogdanov, Slavko and Antonopoulou, Danai and Arzoumanian, Zaven and Bejger, Micha{\l} and Enoto, Teruaki and Esposito, Paolo and Harding, Alice K. and Haskell, Brynmor and Lewandowska, Natalia and Maitra, Chandreyee and Vasilopoulos, Georgios}
}
