scholarly journals Thermal luminosities of cooling neutron stars

2020 ◽  
Vol 496 (4) ◽  
pp. 5052-5071 ◽  
Author(s):  
A Y Potekhin ◽  
D A Zyuzin ◽  
D G Yakovlev ◽  
M V Beznogov ◽  
Yu A Shibanov
Keyword(s):  
Spectral Analysis ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Cooling Curves ◽  
Middle Aged ◽  
Superdense Matter ◽  
Strong Magnetic Fields ◽  
Stellar Core ◽  
Neutron Star Cooling

ABSTRACT Ages and thermal luminosities of neutron stars, inferred from observations, can be interpreted with the aid of the neutron star cooling theory to gain information on the properties of superdense matter in neutron-star interiors. We present a survey of estimated ages, surface temperatures, and thermal luminosities of middle-aged neutron stars with relatively weak or moderately strong magnetic fields, which can be useful for these purposes. The catalogue includes results selected from the literature, supplemented with new results of spectral analysis of a few cooling neutron stars. The data are compared with the theory. We show that overall agreement of theoretical cooling curves with observations improves substantially for models where neutron superfluidity in stellar core is weak.

scholarly journals Onset of superconductivity and retention of magnetic fields in cooling neutron stars

2017 ◽  
Vol 13 (S337) ◽  
pp. 213-216
Author(s):  
Wynn C. G. Ho ◽  
Nils Andersson ◽  
Vanessa Graber
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Minimum Energy ◽  
Meissner Effect ◽  
Energy Conditions ◽  
Field Diffusion ◽  
Neutron Star Cooling ◽  
Proton Pairing

AbstractA superconductor of paired protons is thought to form in the core of neutron stars soon after their birth. Minimum energy conditions suggest that magnetic flux is expelled from the superconducting region due to the Meissner effect, such that the neutron star core retains or is largely devoid of magnetic fields for some nuclear equation of state and proton pairing models. We show via neutron star cooling simulations that the superconducting region expands faster than flux is expected to be expelled because cooling timescales are much shorter than timescales of magnetic field diffusion. Thus magnetic fields remain in the bulk of the neutron star core for at least 106 − 107yr. We estimate the size of flux free regions at 107yr to be ≲ 100m for a magnetic field of 1011G and possibly smaller for stronger field strengths.

scholarly journals Cooling of Neutron Stars: Accurate Treatment of Thermal Conduction

1981 ◽  
Vol 95 ◽  
pp. 339-341
Author(s):  
N. Itoh ◽  
K. Nomoto ◽  
S. Tsuruta ◽  
T. Murai
Keyword(s):  
Thermal Conductivity ◽  
Neutron Star ◽  
Neutron Stars ◽  
Stellar Evolution ◽  
Thermal Conduction ◽  
Stellar Core ◽  
Accurate Treatment ◽  
Neutron Star Cooling

Most of the neutron star cooling calculations with the only exception of Malone's (1974) have assumed an isothermal stellar core. Here we report on a neutron star cooling calculation which makes full use of the stellar evolution code and the recent thermal conductivity calculations by Flowers and Itoh (1976, 1979).

scholarly journals Neutron stars velocities and magnetic fields

2018 ◽  
Vol 172 ◽  
pp. 07002
Author(s):  
Daryel Manreza Paret ◽  
A. Perez Martinez ◽  
Alejandro. Ayala ◽  
G. Piccinelli ◽  
A. Sanchez
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Strange Quark ◽  
Chemical Potential ◽  
Strange Quark Matter ◽  
Strong Magnetic Fields ◽  
Stars Velocities ◽  
Anisotropic Emission

We study a model that explain neutron stars velocities due to the anisotropic emission of neutrinos. Strong magnetic fields present in neutron stars are the source of the anisotropy in the system. To compute the velocity of the neutron star we model its core as composed by strange quark matter and analice the properties of a magnetized quark gas at finite temperature and density. Specifically we have obtained the electron polarization and the specific heat of magnetized fermions as a functions of the temperature, chemical potential and magnetic field which allow us to study the velocity of the neutron star as a function of these parameters.

scholarly journals Cooling of hybrid neutron stars with microscopic equations of state

2020 ◽  
Vol 498 (1) ◽  
pp. 344-354 ◽  
Author(s):  
J-B Wei ◽  
G F Burgio ◽  
H-J Schulze ◽  
D Zappalà
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Equations Of State ◽  
P Wave ◽  
Cooling Curves ◽  
Hartree Fock ◽  
Nuclear Equation Of State ◽  
Neutron Star Cooling ◽  
Quark Models

ABSTRACT We model the cooling of hybrid neutron stars combining a microscopic nuclear equation of state in the Brueckner–Hartree–Fock approach with different quark models. We then analyse the neutron star cooling curves predicted by the different models and single out the preferred ones. We find that the possibility of neutron p-wave pairing can be excluded in our scenario.

scholarly journals Neutron Star Atmospheres

2000 ◽  
Vol 177 ◽  
pp. 613-618
Author(s):  
George G. Pavlov ◽  
V. E. Zavlin
Keyword(s):  
Neutron Star ◽  
Magnetic Fields ◽  
Thermal Radiation ◽  
Neutron Stars ◽  
Optical Radiation ◽  
Superdense Matter ◽  
X Ray ◽  
Fundamental Properties ◽  
Surface Temperatures ◽  
Thin Plasma

AbstractProperties of the thermal radiation emitted by neutron stars (NSs) are determined by thin plasma layers (atmospheres) at their surfaces. The NS atmospheres are very different from those of usual stars due to the immense gravity and huge magnetic fields. Current models of hydrogen NS atmospheres show that the spectra deviate substantially from blackbody spectra of the same temperatures. Comparison of the model spectra with recent observations of soft X-ray and UV-optical radiation of NSs yields the surface temperatures considerably lower than those obtained from the blackbody fits. This conclusion have important implications for theories of NS cooling and for understanding fundamental properties of the superdense matter in the NS interiors.

scholarly journals Magnetic neutron star cooling and microphysics

2018 ◽  
Vol 609 ◽  
pp. A74 ◽  
Author(s):  
A. Y. Potekhin ◽  
G. Chabrier
Keyword(s):  
Neutron Star ◽  
Finite Difference ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Thermodynamic Functions ◽  
Thermal Evolution ◽  
Relative Importance ◽  
Quasistationary Approximation ◽  
Theoretical Predictions ◽  
Neutron Star Cooling

Aims. We study the relative importance of several recent updates of microphysics input to the neutron star cooling theory and the effects brought about by superstrong magnetic fields of magnetars, including the effects of the Landau quantization in their crusts. Methods. We use a finite-difference code for simulation of neutron-star thermal evolution on timescales from hours to megayears with an updated microphysics input. The consideration of short timescales (≲1 yr) is made possible by a treatment of the heat-blanketing envelope without the quasistationary approximation inherent to its treatment in traditional neutron-star cooling codes. For the strongly magnetized neutron stars, we take into account the effects of Landau quantization on thermodynamic functions and thermal conductivities. We simulate cooling of ordinary neutron stars and magnetars with non-accreted and accreted crusts and compare the results with observations. Results. Suppression of radiative and conductive opacities in strongly quantizing magnetic fields and formation of a condensed radiating surface substantially enhance the photon luminosity at early ages, making the life of magnetars brighter but shorter. These effects together with the effect of strong proton superfluidity, which slows down the cooling of kiloyear-aged neutron stars, can explain thermal luminosities of about a half of magnetars without invoking heating mechanisms. Observed thermal luminosities of other magnetars are still higher than theoretical predictions, which implies heating, but the effects of quantizing magnetic fields and baryon superfluidity help to reduce the discrepancy.

scholarly journals The Physics of Soft Gamma Repeaters

2000 ◽  
Vol 195 ◽  
pp. 245-254
Author(s):  
C. Thompson
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Strong Magnetic Fields ◽  
Dominant Source ◽  
Soft Gamma Repeaters ◽  
Physical Diagnostics ◽  
Fireball Model

I describe the evidence that Soft Gamma Repeaters are magnetars—neutron stars in which a decaying magnetic field (rather than rotation) is the dominant source of free energy. The focus here is on the bursting emission of these sources and on direct physical diagnostics of very strong magnetic fields (B ≳ 10 BQED = 4.4 × 1014 G). I also summarize the trapped fireball model of SGR outbursts, the influence of QED processes on their spectra and lightcurves, and the genetic connection between neutron star magnetism and the violent fluid motions in a collapsing supernova core.

Matter in Superstrong Magnetic Fields

1974 ◽  
Vol 53 ◽  
pp. 117-131 ◽  
Author(s):  
M. Ruderman
Keyword(s):  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Strong Magnetic Fields ◽  
Atomic Chains

We consider the structure of atoms and atomic chains in the presence of ultra-strong magnetic fields as might be found in pulsars or neutron stars. Some consequences of these models for neutron star surfaces are mentioned.

scholarly journals Neutron Star Crusts With Magnetic Fields

1994 ◽  
Vol 147 ◽  
pp. 214-238
Author(s):  
D.G. Yakovlev ◽  
A.D. Kaminker
Keyword(s):  
Neutron Star ◽  
Magnetic Fields ◽  
Neutrino Energy ◽  
Temperature Profiles ◽  
Surface Layers ◽  
Strong Magnetic Fields ◽  
Heat Transport Properties ◽  
Neutron Star Cooling ◽  
Radiative Thermal Conductivity ◽  
Degenerate Electron Gas

AbstractThe properties of plasma in neutron star crusts with strong magnetic fields B = 1010 − 1013 G are reviewed: thermodynamic properties (equation of state, entropy, specific heat), transport properties (electron thermal and electrical conductivity of degenerate electron gas, radiative thermal conductivity of very surface nondegenerate layers) and neutrino energy losses. Classical effects of electron Larmor rotation in a magnetic field are considered as well as quantum effects of the electron motion (Landau levels). The influence of the magnetic fields on density and temperature profiles in the surface layers of neutron stars and on neutron star cooling is briefly discussed.

scholarly journals Neutron Star Cooling and the Vela Pulsar

1987 ◽  
Vol 125 ◽  
pp. 456-456
Author(s):  
Ken'ichi Nomoto ◽  
Sachiko Tsuruta
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Cooling Curves ◽  
X Ray ◽  
Vela Pulsar ◽  
Neutron Star Cooling

We have calculated cooling models of young neutron stars.3 The theoretical cooling curves for several models are compared with the Einstein X-ray observations of young supernova remnants (Figure 1).

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