Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A

TL;DR

This paper models how the phase state of triplet superfluid neutrons in a neutron star's core affects its cooling rate, explaining rapid cooling observed in Cassiopeia A without exotic physics.

Contribution

It introduces a model showing multicomponent triplet pairing causes enhanced neutrino emission, leading to rapid cooling consistent with observations.

Findings

Multicomponent triplet pairing increases neutrino losses.

Phase transition triggers rapid cooling.

Model explains Cassiopeia A's cooling without exotic physics.

Abstract

In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.