Quiescent luminosities of accreting neutron stars with different equation of states

Abstract

We model the quiescent luminosity of accreting neutron stars with several equation of states (EOSs), including the effect of pion condensation and superfluidity. As a consequence of comparison with the observations, we show that the results with Togashi EoS (the strong direct Urca process is forbidden) and TM1e EoS (mass at direct Urca process is $2.06M_{\odot }$) can explain the observations well by considering pion condensation and the effect of superfluidity, while LS220 EoS and TM1 EoS can explain the observations well by considering the baryon direct Urca process and the effect of superfluidity. Besides, we compare the results with the observations of a neutron star RX J0812.4-3114 which has the low average mass accretion rate ($⟨\dot{M}⟩\sim (4-15)\times 10^{-12}{M}_{\odot }\mathrm{y}{\mathrm{r}}^{-1}$) but high thermal luminosity ($L_q^{\infty }\sim (0.6-3)\times 10^{33}\mathrm{erg}{\mathrm{s}}^{-1}$), and we suggest that a low-mass neutron star ($<1M_{\odot }$) with minimum cooling can explain the lower limit of the observation of thermal luminosity of RX J0812.4-3114, which is qualitatively consistent with the previous work~\cite{Zhao2019}. However, to explain its upper limit, some other heating mechanisms besides standard deep crustal heating may be needed.

arXiv comment12 pages, 8 figures, accepted by Phys. Rev. D

References in corpus (42)

• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• GW170817: Measurements of Neutron Star Radii and Equation of State
• Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar
• Equations of state for supernovae and compact stars
• The Equation of State from Observed Masses and Radii of Neutron Stars
• Neutrino Emission from Neutron Stars
• Minimal Cooling of Neutron Stars: A New Paradigm
• Crustal Heating and Quiescent Emission from Transiently Accreting Neutron Stars
• Neutron stars - cooling and transport
• The rp Process Ashes from Stable Nuclear Burning on an Accreting Neutron Star
• Relativistic Equation of State for Core-Collapse Supernova Simulations
• The Role of Turbulence in Neutrino-Driven Core-Collapse Supernova Explosions
• Models of crustal heating in accreting neutron stars
• Nuclear equation of state for core-collapse supernova simulations with realistic nuclear forces
• Nuclear composition and heating in accreting neutron-star crusts
• Neutron star cooling
• Screening Effects in Superfluid Nuclear and Neutron Matter within Brueckner Theory
• Further Constraints on Thermal Quiescent X-ray Emission from SAX J1808.4-3658
• Tests of the nuclear equation of state and superfluid and superconducting gaps using the Cassiopeia A neutron star
• Constraints on Thermal X-ray Radiation from SAX J1808.4-3658 and Implications for Neutron Star Neutrino Emission
• The Dipole Magnetic Field and Spin-down Evolutions of The High Braking Index Pulsar PSR J1640-4631
• Cooling of Accretion-Heated Neutron Stars
• Thermal Conductivity of Neutrons in Neutron Star Cores
• Effects of symmetry energy on equation of state for simulations of core-collapse supernovae and neutron-star mergers
• Magnetic neutron star cooling and microphysics
• The Dependence of the Neutrino Mechanism of Core-Collapse Supernovae on the Equation of State
• Thermal state of transiently accreting neutron stars
• Triplet pairing in beta-stable neutron star matter
• Statistical theory of thermal evolution of neutron stars
• The X-ray properties of Be/X-ray pulsars in quiescence
• Influence of Nuclear Reaction Rate Uncertainties on Neutron Star Properties Extracted From X-ray Burst Model-Observation Comparisons
• Internal temperatures and cooling of neutron stars with accreted envelopes
• Neutrino emission from triplet pairing of neutrons in neutron stars
• Statistical theory of thermal evolution of neutron stars - II. Limitations on direct Urca threshold
• Thermal evolution and quiescent emission of transiently accreting neutron stars
• Thermal states of neutron stars with a consistent model of interior
• Neutron star cooling with microscopic equations of state
• Cooling of neutron stars in soft X-ray transients
• Superfluid response and the neutrino emissivity of baryon matter: Fermi-liquid effects
• Neutrino-pair bremsstrahlung in a neutron star crust
• Soft excess in the quiescent Be/X-ray pulsar RX J0812.4-3114

Cited by in corpus (5)

• Impacts of the direct URCA and Superfluidity inside a Neutron Star on Type-I X-Ray Bursts and X-Ray Superbursts
• Accreting neutron stars: heating of the upper layers of the inner crust
• The Impacts of Neutron-Star Structure and Base Heating on Type I X-Ray Bursts and Code Comparison
• Gravitational wave asteroseismology of accreting neutron stars in a steady state
• Quiescent luminosities of transiently accreting neutron stars with neutrino heating due to charged pion decay