scholarly journals A possible way to reconcile long-period precession with vortex pinning in neutron stars

2018 ◽  
Vol 482 (3) ◽  
pp. 3032-3044 ◽  
Author(s):  
O A Goglichidze ◽  
D P Barsukov
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Vortex Pinning ◽  
Component Model ◽  
Observation Data ◽  
Interaction Coefficients ◽  
Long Period

ABSTRACT We propose a possible way to solve the problem of inconsistency between the neutron star long-period precession and superfluid vortex pinning, which is the basis of the most successful theories of pulsar glitches. We assume that the pinning takes place in the region of the neutron star core, which, being magnetically decoupled, can rotate relative to the crust. In the framework of a simple three-component model we show that these two phenomena can coexist in the same pulsar. Some constraints on the formally introduced interaction coefficients following from observation data are formulated.

scholarly journals Nuclear equation of state and neutron star cooling

2017 ◽  
Vol 26 (04) ◽  
pp. 1750015 ◽  
Author(s):  
Yeunhwan Lim ◽  
Chang Ho Hyun ◽  
Chang-Hwan Lee
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
Thermal Evolution ◽  
Observation Data ◽  
Nuclear Equation Of State ◽  
The Core ◽  
Dense Nuclear Matter ◽  
Nuclear Models

In this paper, we investigate the cooling of neutron stars with relativistic and nonrelativistic models of dense nuclear matter. We focus on the effects of uncertainties originated from the nuclear models, the composition of elements in the envelope region, and the formation of superfluidity in the core and the crust of neutron stars. Discovery of [Formula: see text] neutron stars PSR J1614−2230 and PSR J0343[Formula: see text]0432 has triggered the revival of stiff nuclear equation of state at high densities. In the meantime, observation of a neutron star in Cassiopeia A for more than 10 years has provided us with very accurate data for the thermal evolution of neutron stars. Both mass and temperature of neutron stars depend critically on the equation of state of nuclear matter, so we first search for nuclear models that satisfy the constraints from mass and temperature simultaneously within a reasonable range. With selected models, we explore the effects of element composition in the envelope region, and the existence of superfluidity in the core and the crust of neutron stars. Due to uncertainty in the composition of particles in the envelope region, we obtain a range of cooling curves that can cover substantial region of observation data.

scholarly journals Revisiting the Post-glitch Relaxation of the 2000 Vela Glitch with the Neutron Star Equation of States in the Brueckner and Relativistic Brueckner Theories

2021 ◽  
Vol 923 (1) ◽  
pp. 108
Author(s):  
Xinle Shang ◽  
Ang Li
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Component Model ◽  
Short Term ◽  
Strong Suppression ◽  
Stellar Radius ◽  
Equation Of States ◽  
Two Component ◽  
Vela Pulsar

Abstract We revisit the short-term post-glitch relaxation of the Vela 2000 glitch in the simple two-component model of the pulsar glitch by making use of the latest realistic equations of states from the microscopic Brueckner and the relativistic Brueckner theories for neutron stars, which can reconcile with the available astrophysical constraints. We show that to fit both the glitch size and the post-glitch jumps in frequency derivatives approximately 1 minute after the glitch, the mass of the Vela pulsar is necessarily small, and there may be demands for a stiff equation of state (which results in a typical stellar radius larger than ∼12.5 km) and a strong suppression of the pairing gap in the nuclear medium. We discuss the implications of this result on the understanding of pulsar glitches.

scholarly journals Force on a neutron quantized vortex pinned to proton fluxoids in the superfluid core of cold neutron stars

2020 ◽  
Vol 493 (1) ◽  
pp. 382-389 ◽  
Author(s):  
Aurélien Sourie ◽  
Nicolas Chamel
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
General Expression ◽  
Vortex Dynamics ◽  
Cold Neutron ◽  
Vortex Pinning ◽  
Quantized Vortices ◽  
Single Vortex ◽  
The Core ◽  
Superfluid Core

ABSTRACT The superfluid and superconducting core of a cold rotating neutron star (NS) is expected to be threaded by a tremendous number of neutron quantized vortices and proton fluxoids. Their interactions are unavoidable and may have important astrophysical implications. In this paper, the various contributions to the force acting on a single vortex to which fluxoids are pinned are clarified. The general expression of the force is derived by applying the variational multifluid formalism developed by Carter and collaborators. Pinning to fluxoids leads to an additional Magnus type force due to proton circulation around the vortex. Pinning in the core of an NS may thus have a dramatic impact on the vortex dynamics, and therefore on the magnetorotational evolution of the star.

scholarly journals A Gravitational-Wave Perspective on Neutron-Star Seismology

Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 97
Author(s):  
Nils Andersson
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Fundamental Mode ◽  
Compact Binaries

We provide a bird’s-eye view of neutron-star seismology, which aims to probe the extreme physics associated with these objects, in the context of gravitational-wave astronomy. Focussing on the fundamental mode of oscillation, which is an efficient gravitational-wave emitter, we consider the seismology aspects of a number of astrophysically relevant scenarios, ranging from transients (like pulsar glitches and magnetar flares), to the dynamics of tides in inspiralling compact binaries and the eventual merged object and instabilities acting in isolated, rapidly rotating, neutron stars. The aim is not to provide a thorough review, but rather to introduce (some of) the key ideas and highlight issues that need further attention.

Aspects of the Collapse of Compact Objects

1980 ◽  
Vol 4 (1) ◽  
pp. 49-50
Author(s):  
R. A. Gingold ◽  
J. J. Monaghan
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
White Dwarf ◽  
Compact Objects ◽  
Dwarf Star

Misner Thorne and Wheeler (1973), (page 629) suggested that a freshly formed White Dwarf star of several solar masses would, if slowly — rotating, collapse to form a neutron star pancake which would become unstable and eventually produce several, possibly colliding, neutron stars.

scholarly journals Remnant massive neutron stars of binary neutron star mergers: Evolution process and gravitational waveform

2013 ◽  
Vol 88 (4) ◽  
Author(s):  
Kenta Hotokezaka ◽  
Kenta Kiuchi ◽  
Koutarou Kyutoku ◽  
Takayuki Muranushi ◽  
Yu-ichiro Sekiguchi ◽  
...  
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Evolution Process ◽  
Binary Neutron Star

DO YOUNG NEUTRON STARS WHICH SHOW THEMSELVES AS AXPs AND SGRs ACCRETE?

2003 ◽  
Vol 12 (05) ◽  
pp. 825-831 ◽  
Author(s):  
S. O. TAGIEVA ◽  
E. YAZGAN ◽  
A. ANKAY
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Supernova Explosion ◽  
X Ray ◽  
X Ray Binaries

We examined the fall-back disk models, and in general accretion, proposed to explain the properties of AXPs and SGRs. We checked the possibility of some gas remaining around the neutron star after a supernova explosion. We also compared AXPs and SGRs with the X-ray pulsars in X-ray binaries. We conclude that the existing models of accretion from a fall-back disk are insufficient to explain the nature of AXPs and SGRs.

Rotation of a two-component model neutron star in the GTR

Astrophysics ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 260-266 ◽  
Author(s):  
D. M. Sedrakian
Keyword(s):  
Neutron Star ◽  
Component Model ◽  
Two Component

scholarly journals Quadrupole moments of rotating compact stars

2012 ◽  
Vol 8 (S291) ◽  
pp. 536-536
Author(s):  
Martin Urbanec ◽  
John Miller ◽  
Zdenek Stuchlik
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Strange Star ◽  
Compact Stars ◽  
Quadrupole Moments ◽  
Strange Stars

AbstractWe present quadrupole moments of rotating neutron and strange stars calculated using standard Hartle Thorne approach. We demonstrate differences between neutron and strange star parameters connected with quadrupole moments and how this parameters could be, in the case of neutron stars, approximated almost independently on neutron star equation of state.

scholarly journals 1S0 Pairing Gaps, Chemical Potentials and Entrainment Matrix in Superfluid Neutron-Star Cores for the Brussels–Montreal Functionals

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 470
Author(s):  
Valentin Allard ◽  
Nicolas Chamel
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Physical Meaning ◽  
Outer Core ◽  
Time Dependent ◽  
Hartree Fock ◽  
Chemical Potentials ◽  
Bogoliubov Equations ◽  
Flow Velocities

Temperature and velocity-dependent 1S0 pairing gaps, chemical potentials and entrainment matrix in dense homogeneous neutron–proton superfluid mixtures constituting the outer core of neutron stars, are determined fully self-consistently by solving numerically the time-dependent Hartree–Fock–Bogoliubov equations over the whole range of temperatures and flow velocities for which superfluidity can exist. Calculations have been made for npeμ in beta-equilibrium using the Brussels–Montreal functional BSk24. The accuracy of various approximations is assessed and the physical meaning of the different velocities and momentum densities appearing in the theory is clarified. Together with the unified equation of state published earlier, the present results provide consistent microscopic inputs for modeling superfluid neutron-star cores.

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