Phase Transition Effects on the Dynamical Stability of Hybrid Neutron Stars

Autor(es)

Pereira, Jonas P. ^{[1, 2, 3]} ; Flores, Cesar V. ^{[3, 4]} ; Lugones, German ^[3]

Afiliação do(s) autor(es)

^[1] Univ Southampton, Math Sci, Southampton SO17 1BJ, Hants - England

^[2] Univ Southampton, STAG Res Ctr, Southampton SO17 1BJ, Hants - England

^[3] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Ave Estados, 5001 Bangu, BR-09210170 Santo Andre, SP - Brazil

^[4] Univ Fed Maranhao, Dept Fis, Campus Univ Bacanga, BR-65080805 Sao Luis, Maranhao - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 860, n. 1 JUN 10 2018.
• Citações Web of Science: 9

Resumo

We study radial oscillations of hybrid nonrotating neutron stars composed by a quark matter core and hadronic external layers. At first, we physically deduce the junction conditions that should be imposed between the two phases in these systems when perturbations take place. Then we compute the oscillation spectrum focusing on the effects of slow and rapid phase transitions at the quark-hadron interface. We use a generic MIT-bag model for quark matter and a relativistic mean field theory for hadronic matter. In the case of rapid transitions at the interface, we find a general relativistic version of the reaction mode that has similar properties as its classical counterpart. We also show that the usual static stability condition partial derivative M/partial derivative rho(c) >= 0, where rho(c) is the central density of a star whose total mass is M, always remains true for rapid transitions but breaks down in general for slow transitions. In fact, for slow transitions, we find that the frequency of the fundamental mode can be a real number (indicating stability) even for some branches of stellar models that verify partial derivative M/partial derivative rho(c) <= 0. Thus, when secular instabilities are suppressed, as expected below some critical stellar rotation rate, the existance of twin or even triplet stars with the same gravitational mass but different radii, with one of the counterparts having partial derivative M/partial derivative rho(c) <= 0, would be possible. We explore some astrophysical consequences of these results. (AU)

• Processo FAPESP: 15/04174-9 - Algumas consequências da microfísica de volumes e superfícies em sistemas compactos
• Beneficiário: Jonas Pedro Pereira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/21384-2 - Asterosismologia de oscilações quase periódicas e restrições a modelos de estrelas de nêutrons híbridas
• Beneficiário: Jonas Pedro Pereira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado