2020/08/31 by Rafael C. Nunes, Jaziel G. Coelho, José C. N. de Araujo
Physics and Astronomy · #Astrophysical Phenomena and Observations #Binary number #Component (thermodynamics) #Constraint (computer-aided design) #Equation of state #Gamma-ray bursts and supernovae #Gravitation #Gravitational wave #Hydrostatic equilibrium #Neutron star #Object (grammar) #Pulsars and Gravitational Waves Research #astro-ph.HE #gr-qc
paper · pdf · doi:10.1140/epjc/s10052-020-08695-0
published as Eur. Phys. J. C 80, 1115 (2020) · 10 pages, 4 Figues, 1 Table. Matches the version published in EPJC
openalex created_date 2020/09/01 · openalex publication_date 2020/12/01 · arxiv created 2020/12/04 · arxiv updated 2020/12/07 · openalex updated_date 2026/08/06
Abstract 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+0.08-0.09 M_\odot <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>.</mml:mo> <mml:msubsup> <mml:mn>59</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>0.09</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.08</mml:mn> </mml:mrow> </mml:msubsup> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> </mml:mrow> </mml:math> 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.