Stochastic processes for pulsar timing noise: fluctuations in the internal and external torques

Abstract

Young pulsars deviate from a perfectly regular spin-down by two non-deterministic phenomena: impulsive glitches and timing noise. Both phenomena are interesting per se, and may provide insights into the superfluid properties of neutron stars, but they also act as a barrier to high-precision pulsar timing and gravitational wave experiments. We study a minimal stochastic model to describe the spin-down of a multicomponent neutron star, with fluctuations in both the internal and external torques. The power spectral density and timing noise strength of this kind of model can be obtained analytically, and compared with known results from pulsar timing observational campaigns. In particular, the presence of flat regions of the power spectral density can be interpreted as a signature of the presence of internal superfluid components. We also derive the expected scaling of the timing noise strength with the pulsar's rotational parameters (or characteristic age). Therefore, the present framework offers a theoretical guideline to interpret the observed features of timing noise in both single pulsars and across pulsar population.

17 pages, 6 figures

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Cited by in corpus (11)

• The Science of the Einstein Telescope
• Insights into the physics of neutron star interiors from pulsar glitches
• CHIME/FRB/Pulsar discovery of a nearby long period radio transient with a timing glitch
• The Green Bank North Celestial Cap Survey IX: Timing Follow-up for 128 Pulsars
• Constraints on Undetected Long-Period Binaries in the Known Pulsar Population
• Emergent chirality and superfluidity of parity-doubled baryons in neutron stars
• How much spin wandering can continuous gravitational wave search algorithms handle?
• Hierarchical Bayesian estimation of population-level torque law parameters from anomalous pulsar braking indices
• Pulse frequency variations and timing noise of MXB 0656-072 during the 2007-2008 type I outbursts and implications for its magnetic field
• Timing results of 22 years for PSR J0922+0638
• Measuring the crust-superfluid coupling time-scale for 105 UTMOST pulsars with a Kalman filter