Constraining Superfluidity in Dense Matter from the Cooling of Isolated Neutron Stars

TL;DR

This paper uses neutron star cooling data to quantitatively constrain superfluid and superconducting critical temperatures in dense matter, providing new estimates and uncertainties that depend on the included data set.

Contribution

It introduces a new method to analyze neutron star cooling data, yielding the best-fit superfluid and superconducting critical temperatures with associated uncertainties.

Findings

Neutron triplet critical temperature is approximately 2.09e8 K.

Proton singlet critical temperature is approximately 7.59e9 K.

Including different neutron stars alters the estimated critical temperatures.

Abstract

We present a quantitative analysis of superfluidity and superconductivity in dense matter from observations of isolated neutron stars in the context of the minimal cooling model. Our new approach produces the best fit neutron triplet superfluid critical temperature, the best fit proton singlet superconducting critical temperature, and their associated statistical uncertainties. We find that the neutron triplet critical temperature is likely $2.09^{+4.37}_{-1.41} \times 10^{8}$ K and that the proton singlet critical temperature is $7.59^{+2.48}_{-5.81} \times 10^{9}$ K. However, we also show that this result only holds if the Vela neutron star is not included in the data set. If Vela is included, the gaps increase significantly to attempt to reproduce Vela's lower temperature given its young age. Further including neutron stars believed to have carbon atmospheres increases the neutron critical temperature and decreases the proton critical temperature. Our method demonstrates that continued observations of isolated neutron stars can quantitatively constrain the nature of superfluidity in dense matter.