Lower limit on the heat capacity of the neutron star core

Andrew Cumming; Edward F. Brown; Farrukh J. Fattoyev; C. J. Horowitz; Dany Page; Sanjay Reddy

doi:10.1103/physrevc.95.025806

Heat capacity of the neutron star inner crust within an extended nuclear statistical equilibrium model

Physical Review C ◽

10.1103/physrevc.92.055804 ◽

2015 ◽

Vol 92 (5) ◽

Cited By ~ 14

Author(s):

S. Burrello ◽

F. Gulminelli ◽

F. Aymard ◽

M. Colonna ◽

Ad. R. Raduta

Keyword(s):

Heat Capacity ◽

Neutron Star ◽

Equilibrium Model ◽

Statistical Equilibrium

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Superconducting States in Nature

Superconducting State ◽

10.1093/oso/9780198845331.003.0010 ◽

2021 ◽

pp. 429-436

Author(s):

Vladimir Z. Kresin ◽

Sergei G. Ovchinnikov ◽

Stuart A. Wolf

Keyword(s):

Heat Capacity ◽

Neutron Star ◽

Pair Correlation ◽

Rotation Period ◽

Biologically Active ◽

Electron Pairs ◽

Active Systems ◽

Atomic Nuclei ◽

Josephson Tunnelling ◽

Rigid Model

This chapter discusses superconducting states in nature. The absence of resistance is the most remarkable manifestation of the superconducting state. But pair correlation is a general phenomenon that can be manifested in various systems, such as atomic nuclei, where the pairing is manifested in spectra, especially via the odd–even effect (the presence of unpaired nucleons makes it possible for nuclei to absorb a lower frequency of radiation than nuclei with an even number of nucleons can) and in the amplitudes of their momenta of inertia, which are smaller than in a rigid model. Another system, the neutron star, has an entirely different spatial scale. However, its low heat capacity leads to its rapid cooling, and the existence of a vortex structure affects the star’s rotation period. Finally, biologically active systems contain delocalised electrons, and the formation of electron pairs affects charge transfer, which is similar to Josephson tunnelling.

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Constraints on neutron stars equation of state using the tidal deformability derived from BNS mergers

HNPS Proceedings ◽

10.12681/hnps.2989 ◽

2020 ◽

Vol 27 ◽

pp. 95

Author(s):

Alkiviadis Kanakis-Pegios ◽

Charalampos Moustakidis

Keyword(s):

Neutron Star ◽

Equation Of State ◽

Binary System ◽

Neutron Stars ◽

Effective Mass ◽

Lower Limit ◽

Mathematical Formalism ◽

Love Number ◽

Binary Neutron Star ◽

Upper Limit

The purpose of this work is the study of neutron stars (NS) equation of state (EOS) using constraints on tidal deformability derived from observation of binary neutron star (BNS) mergers, such as GW170817. The mathematical formalism is introduced, and then for a variety of EOS the system is solved numerically, allowing us to determine the mass, the radius, the tidal love number and the tidal deformability of the NS, each one of them unique for each EOS. Moreover, for a fixed value of chirp mass under the assumption that m2<m1 (where m1 is the heavier component mass of BNS system), the effective (mass-weighted) tidal deformability of the binary system is determined for each EOS. We consider both an upper limit (GW170817) and a lower limit (AT2017gfo) for the effective tidal deformability. Also, we construct the Λ1-Λ2 space and we compare the behavior of EOS with the most recent LIGO’s data. We found out that the most EOS models give values for the effective tidal deformability less than the upper limit and that the most stiff EOS are excluded.

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The special point on the hybrid star mass–radius diagram and its multi–messenger implications

The European Physical Journal Special Topics ◽

10.1140/epjst/e2020-000235-5 ◽

2020 ◽

Vol 229 (22-23) ◽

pp. 3663-3673

Author(s):

Mateusz Cierniak ◽

David Blaschke

Keyword(s):

Neutron Star ◽

Lower Limit ◽

Quark Matter ◽

Inner Core ◽

Special Point ◽

Star Mass ◽

The Difference ◽

Hybrid Stars ◽

Onset Of Deconfinement ◽

Generic Constant

AbstractWe show the existence and investigate the location of the special point (SP) in which hybrid neutron star mass-radius (M-R) curves have to cross each other when they belong to a class of hybrid equation of state (EoS) constructed with generic constant–speed–of–sound (CSS) quark matter models for which the onset deconfinement is varied. We demonstrate that for a three-parameter CSS model the position of the SP in the M-R diagram is largely independent of the choice of the hadronic EoS, but in dependence on the stiffness of the quark matter EoS it spans a region that we identify. We find that the difference between the maximum mass and the SP mass depends on the mass at the onset of deconfinement so that an upper limit of 0.19 M⊙ for this difference is obtained from which a lower limit on the radius of hybrid stars is deduced. Together with a lower limit on the radius of hadronic stars, derived from a class of reasonably soft hadronic EoS including hyperons, we identify a region in the M-R diagram which can be occupied only by hybrid stars. Accordingly, we suggest that a NICER radius measurement on the massive pulsar PSR J0740 + 6620 in the range of 8.6-11.9 km would indicate that this pulsar is a hybrid neutron star with deconfined quark matter in the inner core.

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THE FATE OF Cyg X-1: AN EMPIRICAL LOWER LIMIT ON BLACK-HOLE-NEUTRON-STAR MERGER RATE

The Astrophysical Journal ◽

10.1088/2041-8205/742/1/l2 ◽

2011 ◽

Vol 742 (1) ◽

pp. L2 ◽

Cited By ~ 14

Author(s):

Krzysztof Belczynski ◽

Tomasz Bulik ◽

Charles Bailyn

Keyword(s):

Black Hole ◽

Neutron Star ◽

Lower Limit ◽

Merger Rate

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Supernovae and interstellar gas dynamics

Symposium - International Astronomical Union ◽

10.1017/s0074180900100774 ◽

1967 ◽

Vol 31 ◽

pp. 117-119

Author(s):

F. D. Kahn ◽

L. Woltjer

Keyword(s):

Lower Limit ◽

High Velocity ◽

Gas Dynamics ◽

Interstellar Cloud ◽

Interstellar Gas ◽

Random Motions ◽

Relativistic Particles

The efficiency of the transfer of energy from supernovae into interstellar cloud motions is investigated. A lower limit of about 0·002 is obtained, but values near 0·01 are more likely. Taking all uncertainties in the theory and observations into account, the energy per supernova, in the form of relativistic particles or high-velocity matter, needed to maintain the random motions in the interstellar gas is estimated as 1051·4±1ergs.

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