Measuring glitch recoveries and braking indices with Bayesian model selection

Pulsars with large spin-up glitches typically exhibit braking indices greater than 3, indicating that internal torques dominate their rotational evolution between glitches. Researchers analyzed 157 glitches from 35 pulsars monitored by the Jodrell Bank Observatory using Bayesian model selection to determine post-glitch recovery parameters. They found strong correlations between glitch-induced spin-down rate changes and pulsar spin parameters, including a notable link between interglitch braking indices and spin-down rates. The study also suggests that the ratio of glitch-induced spin-down rate change to the second frequency derivative can estimate glitch recurrence times for certain pulsars. For younger pulsars (less than 10,000 years), external torques, such as electromagnetic dipole radiation, may dominate the observed braking indices, which could approach 3.

Liu, Y., Keith, M. J., Antonopoulou, D., Weltevrede, P., Shaw, B., Stappers, B. W., Lyne, A. G., Mickaliger, M. B., & Basu, A. (2024). Measuring glitch recoveries and braking indices with Bayesian model selection. Monthly Notices of the Royal Astronomical Society, 532(1), 859–882. https://doi.org/10.1093/mnras/stae1499