The hottest superfluid and superconductor in the Universe: Discovery and nuclear physics implications

TL;DR

This paper discusses how astronomical observations of neutron stars reveal superfluidity and superconductivity in their cores, providing insights into nuclear physics beyond laboratory capabilities.

Contribution

It presents new observational evidence of superfluidity and superconductivity in neutron star cores and explores their implications for nuclear physics and pulsar glitch models.

Findings

First direct evidence of superfluidity in neutron star cores

Constraints on neutron superfluidity from X-ray burst observations

Core superfluid participation in pulsar glitches

Abstract

We present recent work on using astronomical observations of neutron stars to reveal unique insights into nuclear matter that cannot be obtained from laboratories on Earth. First, we discuss our measurement of the rapid cooling of the youngest neutron star in the Galaxy; this provides the first direct evidence for superfluidity and superconductivity in the supra-nuclear core of neutron stars. We show that observations of thermonuclear X-ray bursts on neutron stars can be used to constrain properties of neutron superfluidity and neutrino emission. We describe the implications of rapid neutron star rotation rates on aspects of nuclear and superfluid physics. Finally, we show that entrainment coupling between the neutron superfluid and the nuclear lattice leads to a less mobile crust superfluid; this result puts into question the conventional picture of pulsar glitches as being solely due to the crust superfluid and suggests that the core superfluid also participates.