Delayed Thermal Relaxation of Rapidly Cooling Neutron Stars: Nucleon Superfluidity and Non-nucleon Particles
arXiv:2503.14059 · doi:10.3847/1538-4357/add734
Abstract
The thermal relaxation time of neutron stars, typically defined by a sudden drop in surface temperature, is usually on the order of 10 to 100 years. In this study, we investigate neutron star thermal relaxation by incorporating nucleon superfluidity and non-nucleonic particles, specifically considering hyperons as a representative case. We find that rapidly cooling neutron stars driven by neutron superfluidity and direct Urca processes demonstrate delayed thermal relaxation under specific physical conditions. The former acquires that the neutron critical temperature is small enough, whereas the latter depends on the presence of a small core that permits direct Urca processes. To explore these scenarios, we propose simple theoretical frameworks to describe these delayed thermal relaxation behaviors and discuss how an recently-established enhanced modified Urca rate influences the relaxation time. By confronting the theoretical results with the observation of Cassiopeia A, we can effectively constrain the maximum neutron critical temperature.
version accepted for publication in ApJ
References in corpus (13)
- GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
- Rapid Cooling of the Neutron Star in Cassiopeia A Triggered by Neutron Superfluidity in Dense Matter
- An updated mass-radius analysis of the 2017-2018 NICER data set of PSR J0030+0451
- The Radius of the High-mass Pulsar PSR J0740+6620 with 3.6 yr of NICER Data
- Neutron star cooling: Theoretical aspects and observational constraints
- Astrophysical implications on hyperon couplings and hyperon star properties with relativistic equations of states
- Effects of -meson on properties of hyperon stars in density dependent relativistic mean field model
- Cooling of hypernuclear compact stars: Hartree-Fock models and high-density pairing
- Symmetry energy effect on the secondary component of GW190814 as a neutron star
- Model-independent constraints on superfluidity from the cooling neutron star in Cassiopeia A
- Revisiting the thermal relaxation of neutron stars
- Density-dependent relativistic mean-field model for hypernuclei
- Exploring nuclear force with pulsar glitch observation