Self-similarity relations for cooling superfluid neutron stars

Abstract

We consider models of cooling neutron stars with nucleon cores which possess moderately strong triplet-state superfluidity of neutrons. When the internal temperature drops below the maximum of the critical temperature over the core, $T_{\mathrm{C}}$, this superfluidity sets in. It produces a neutrino outburst due to Cooper pairing of neutrons which greatly accelerates the cooling. We show that the cooling of the star with internal temperature $T$ within $0.6T_{\mathrm{C}}\lesssim T\le T_{\mathrm{C}}$ is described by analytic self-similar relations. A measurement of the effective surface temperature of the star and its decline, supplemented by assumptions on star's mass, radius and composition of heat-blanketing envelope, allows one to construct a family of cooling models parametrized by the value of $T_{\mathrm{C}}$. Each model reconstructs cooling history of the star including its neutrino emission level before neutron superfluidity onset and the intensity of Cooper pairing neutrinos. The results are applied to interpret the observations of the neutron star in the Cassiopeia A supernova remnant.

10 pages, 14 figures, 2 tables; published in MNRAS. In version 2, typos and references corrected

References in corpus (2)

• Rapid Cooling of the Neutron Star in Cassiopeia A Triggered by Neutron Superfluidity in Dense Matter
• Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant

Cited by in corpus (6)

• Model-independent constraints on superfluidity from the cooling neutron star in Cassiopeia A
• Constraints on neutron star superfluidity from the cooling neutron star in Cassiopeia A using all Chandra ACIS-S observations
• Neutrino luminosities and heat capacities of neutron stars in analytic form
• Cooling of neutron stars with diffusive envelopes
• Hybrid cooling of the Cassiopeia A neutron star
• Cooling of the Cassiopeia A neutron star and the effect of diffusive nuclear burning