Cooling of Hybrid Stars with Spin Down Compression

TL;DR

This paper investigates how the cooling behavior of hybrid stars is affected by spin-down processes, revealing that rotation influences neutrino emission and temperature evolution, aligning better with pulsar data.

Contribution

It introduces a detailed model of hybrid star cooling that accounts for spin-down effects and compares rotational and static models, highlighting the importance of rotation in thermal evolution.

Findings

Cooling curves depend on magnetic field when direct Urca reactions occur.

Rotational models show higher temperatures than static models.

Predicted temperatures match pulsar observations, unlike static models.

Abstract

We study the cooling of hybrid stars coupling with spin-down. Due to the spin-down of hybrid stars, the interior density continuously increases, different neutrino reactions may be triggered(from the modified Urca process to the quark and nucleon direct Urca process) at different stages of evolution. We calculate the rate of neutrino emissivity of different reactions and simulate the cooling curves of the rotational hybrid stars. The results show the cooling curves of hybrid stars clearly depend on magnetic field if the direct urca reactions occur during the spin-down. Comparing the results of the rotational star model with the transitional static model, we find the cooling behavior of rotational model is more complicated, the temperature of star is higher, especially when direct urca reactions appear in process of rotation. And then we find that the predicted temperatures of some rotating hybrid stars are compatible with the pulsar's data which are contradiction with the results of transitional method.