Pinning Down the Superfluid and Nuclear Equation of State and Measuring Neutron Star Mass Using Pulsar Glitches

We study the cooling of isolated neutron stars with particular regard to the importance of nuclear pairing gaps. A microscopic nuclear equation of state derived in the Brueckner-Hartree-Fock approach is used together with compatible neutron and proton pairing gaps. We then study the effect of modifying the gaps on the final deduced neutron star mass distributions. We find that a consistent description of all current cooling data can be achieved and a reasonable neutron star mass distribution can be predicted employing the (slightly reduced by about 40%) proton 1S0 Bardeen-Cooper-Schrieffer (BCS) gaps and no neutron 3P2 pairing.

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Neutron star masses

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312023423 ◽

2012 ◽

Vol 8 (S291) ◽

pp. 146-146

Author(s):

David Nice

Keyword(s):

Neutron Star ◽

Equation Of State ◽

Nuclear Matter ◽

Observational Data ◽

Mass Distribution ◽

Binary Star ◽

Star Mass ◽

Star Evolution ◽

Neutron Star Mass ◽

Present Understanding

AbstractNeutron star masses can be inferred from observations of binary pulsar systems, particularly by the measurement of relativistic phenomena within these orbits. The observed distribution of masses can be used to infer or constrain the equation of state for nuclear matter and to study astrophysical processes such as supernovae and binary star evolution. In this talk, I will review our present understanding of the neutron star mass distribution with an emphasis on the observational data.

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NEUTRON STAR MASS CORRELATION WITH SOUND VELOCITY AND INCOMPRESSIBILITY AT THE STAR CENTER IN THE POLYTROPIC APPROXIMATION

International Journal of Modern Physics D ◽

10.1142/s0218271810017974 ◽

2010 ◽

Vol 19 (08n10) ◽

pp. 1575-1582

Author(s):

L. FERRARI ◽

P. C. R. ROSSI ◽

M. MALHEIRO

Keyword(s):

Neutron Star ◽

Equation Of State ◽

Nuclear Matter ◽

Sound Velocity ◽

Mean Field ◽

Star Mass ◽

Mean Field Models ◽

Neutron Star Mass ◽

Analytic Expressions ◽

Walecka Model

In this paper we use a polytropic approximation to the equation of state for the interior of neutrons stars, described by relativistic hadronic mean field models. In this approximation, it is possible to obtain analytic expressions for the sound velocity and the incompressibility at the star center. We found a correlation between these quantities and the star mass. Using two well-known parametrizations of the nonlinear Walecka model for nuclear matter composed only of protons, neutrons and electron in β equilibrium, we obtain for a star mass of 1.43 M⊙ a central incompressibility Kc = (3000±100), around ten times the nuclear matter incompressibility, and a central sound velocity (v/c)2 ~ 0.3.

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CONSISTENT THREE-BODY FORCE WITH BONN B POTENTIAL AND NEUTRON STAR STRUCTURE

International Journal of Modern Physics E ◽

10.1142/s0218301310016156 ◽

2010 ◽

Vol 19 (08n09) ◽

pp. 1727-1733 ◽

Cited By ~ 1

Author(s):

Z. H. LI ◽

U. LOMBARDO ◽

H.-J. SCHULZE ◽

W. ZUO

Keyword(s):

Neutron Star ◽

Equation Of State ◽

Symmetry Energy ◽

Body Force ◽

Nucleon Force ◽

Nucleon Potential ◽

Saturation Properties ◽

Nuclear Equation Of State ◽

Neutron Star Mass ◽

Three Body

Microscopic three-nucleon force consistent with the Bonn B two-nucleon potential is constructed, which includes Δ(1232), Roper, and nucleon-antinucleon excitation contributions. Recent results for the choice of the meson parameters are discussed. The forces are used in Brueckner calculations and the saturation properties of nuclear matter are determined. At the high densities, the nuclear equation of state and the symmetry energy are calculated. The corresponding neutron star mass-radius relations are presented.

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