Constraints on pulsar masses from the maximum observed glitch

• Published in: Nature astronomy Vol. 1; no. 7
• Main Authors: Pizzochero, P. M., Antonelli, M., Haskell, B., Seveso, S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-07-2017; Nature Publishing Group
• Subjects: 639/33/34/864; 639/33/34/867; 639/766/387/1127; Astronomy; Astrophysics and Cosmology; Neutron stars; Neutrons; Physics; Physics and Astronomy; Pulsars
• ISSN: 2397-3366; 2397-3366
• DOI: 10.1038/s41550-017-0134

Neutron stars are unique cosmic laboratories in which fundamental physics can be probed in extreme conditions not accessible to terrestrial experiments. In particular, the precise timing of rotating magnetized neutron stars (pulsars) reveals sudden jumps in rotational frequency in these otherwise steadily spinning-down objects. These ‘glitches’ are thought to be due to the presence of a superfluid component in the star, and offer a unique glimpse into the interior physics of neutron stars. In this paper we propose an innovative method to constrain the mass of glitching pulsars, using observations of the maximum glitch observed in a star, together with state-of-the-art microphysical models of the pinning interaction between superfluid vortices and ions in the crust. We study the properties of a physically consistent angular momentum reservoir of pinned vorticity, and we find a general inverse relation between the size of the maximum glitch and the pulsar mass. We are then able to estimate the mass of all the observed glitchers that have displayed at least two large events. Our procedure will allow current and future observations of glitching pulsars to constrain not only the physics of glitch models but also the superfluid properties of dense hadronic matter in neutron star interiors.
Using an innovative method, the mass of a pulsar can be constrained using the maximum ‘glitch’ in the star’s rotational frequency: the bigger the glitch, the lower the mass. This method is used to estimate the mass of all observed glitchers.