Weighing massive neutron star with screening gravity: a look on PSR J0740+6620 and GW190814 secondary component

Autor(es)

Nunes, Rafael C. ^[1] ; Coelho, Jaziel G. ^{[1, 2]} ; de Araujo, Jose C. N. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, Div Astrofis, Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Tecnol Fed Parana, Dept Fis, BR-85884000 Medianeira, PR - Brazil

• Tipo de documento: Artigo Científico
• Fonte: EUROPEAN PHYSICAL JOURNAL C; v. 80, n. 12 DEC 3 2020.
• Citações Web of Science: 9

Resumo

Neutron stars (NSs) are excellent natural laboratories to constrain gravity on strong field regime and nuclear matter in extreme conditions. Motivated by the recent discovery of a compact object with 2.59-0.09+0.08</mml:msubsup><mml:msub>M circle dot in the binary merger GW190814, if this object was a NS, it serves as a strong constraint on the NS equation of state (EoS), ruling out several soft EoSs favored by GW170817 event. In this work, we revisit the question of the maximum mass of NSs considering a chameleon screening (thin-shell effect) on the NS mass-radius relation, where the microscopic physics inside the NS is given by realistic soft EoSs. We find that from appropriate and reasonable combination of modified gravity, rotation effects and realistic soft EoSs, that it is possible to achieve high masses and explain GW190814 secondary component, and in return also NSs like PSR J0740 + 6620 (the most NS massive confirmed to date). It is shown that gravity can play an important role in estimating maximum mass of NSs, and even with soft EoSs, it is possible to generate very high masses. Therefore, in this competition of hydrostatic equilibrium between gravity and pressure (from EoS choice), some soft EoSs, in principle, cannot be completely ruled out without first taking into account gravitational effects. (AU)

• Processo FAPESP: 13/26258-4 - Matéria superdensa no universo
• Beneficiário: Manuel Máximo Bastos Malheiro de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/18036-5 - Investigando aspectos físicos além do modelo padrão ligados aos temas de energia escura, gravidade modificada, neutrinos e ondas gravitacionais
• Beneficiário: Rafael da Costa Nunes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado