Understanding millisecond pulsar spin noise and neutron star physics
In this project, we performed an analysis of millisecond pulsar spin noise using the first data release (DR1) of the International Pulsar Timing Array (IPTA) collaboration. We were particularly interested in determining whether the amplitude of timing residuals, induced by this noise process, keeps growing with longer observations or eventually flattens. We also considered a physical model of millisecond pulsar spin noise, where the noise process is driven by the superfluid turbulence in the core of a neutron star. Our key results:
- Spin noise in IPTA DR1 pulsars shows significant evidence neither in favor of the turnover nor against it.
- Without the spectral turnover, the superfluid turbulence model ends up as a nearly power-law spectrum with a fixed slope and variable amplitude. For these reasons, a few pulsars with the spin noise with a different spectral slope strongly disfavor this model.
Boris Goncharov, Xing-Jiang Zhu, Eric Thrane
Artist's sketch of accreting neutron star, a possible source of gravitational waves. Image: NASA.