Impact of the hot inner crust on compact stars at finite temperature
2024 (Engelska)Ingår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 687, artikel-id A236Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
We conducted a study on the thermal properties of stellar matter with the nuclear energy density functional BCPM. This functional is based on microscopic Brueckner–Hartree–Fock calculations and has demonstrated success in describing cold neutron stars. To enhance its applicability in astrophysics, we extended the BCPM equation of state to finite temperature for β-stable neutrino-free matter, taking into consideration the hot inner crust. Such an equation of state holds significant importance for hot compact objects, particularly those resulting from a binary neutron star merger event. Our exploration has shown that with increasing temperature, there is a fast decrease in the crust-core transition density, suggesting that for hot stars it is not realistic to assume a fixed value of this density. The microscopic calculations also reveal that the presence of nuclear clusters persists up to T = 7.21 MeV, identified as the limiting temperature of the crust. Above this threshold, the manifestation of clusters is not anticipated. Below this temperature, clusters within the inner crust are surrounded by uniform matter with varying densities, allowing for the distinction between the upper and lower transition density branches. Moreover, we computed mass–radius relations of neutron stars, assuming an isothermal profile for β-stable neutron star matter at various temperature values. Our findings highlight the significant influence of the hot inner crust on the mass–radius relationship, leading to the formation of larger and more inflated neutron stars. Consequently, under our prescription, the final outcome is a unified equation of state at finite temperature.
Ort, förlag, år, upplaga, sidor
EDP Sciences , 2024. Vol. 687, artikel-id A236
Nyckelord [en]
dense matter, equation of state, stars: interiors, stars: neutron
Nationell ämneskategori
Astronomi, astrofysik och kosmologi
Identifikatorer
URN: urn:nbn:se:kth:diva-366399DOI: 10.1051/0004-6361/202450305ISI: 001269460100007Scopus ID: 2-s2.0-85198946694OAI: oai:DiVA.org:kth-366399DiVA, id: diva2:1982485
Anmärkning
QC 20250708
2025-07-082025-07-082025-07-08Bibliografiskt granskad