The cooling of neutron stars has proven to be a fantastic way of probing the interior of these objects. Many works were dedicated to investigating several aspects of this rich and complicated phenomena. Our current understanding of the thermal evolution of these objects tells us that they cool down mainly due to two mechanisms: neutrino emission from their interior, and photon emission from the surface. Initially, the neutrino emission from the interior dominates the cooling. After this neutrino dominated era, when the interiors are cool enough that neutrino emission becomes less relevant, the cooling is driven by photon emission from its surface. Furthermore, the significant differences between the structure of the star’s core and crust (the former is composed of a degenerate interacting gas, whereas the latter is mostly crystalline) lead to a thermal decoupling between them for the first (approximately) 100 years of thermal evolution - known as the thermal relaxation time. In this presentation I will revisit the thermal relaxation process for neutron stars. I will show that differently than what was previously thought possible, neutron stars under specific conditions may exhibit abnormally high thermal relaxation times. In order to understand under which conditions such phenomena may take place we will thoroughly discuss the physics of neutron star cooling and energy transport.
Organized by: Tuhin Malik