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Related papers: Bulk viscosity in neutron stars with hyperon cores

200 papers

We present some results about a novel damping mechanism of r-mode oscillations in neutron stars due to processes that change the number of protons, neutrons and electrons. Deviations from equilibrium of the number densities of the various…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Massimo Mannarelli , Giuseppe Colucci , Cristina Manuel

Viscosity driven bar mode secular instabilities of rapidly rotating neutron stars are studied using LORENE/Nrotstar code. These instabilities set a more rigorous limit to the rotation frequency of neutron star than the Kepler frequency/mass…

High Energy Astrophysical Phenomena · Physics 2018-04-30 Arkadip Basak

The loss of angular momentum due to unstable r-modes in hot young neutron stars has been proposed as a mechanism for achieving the spin rates inferred for young pulsars. One factor that could have a significant effect on the action of the…

Astrophysics · Physics 2009-11-07 Anna. L. Watts , Nils. Andersson

We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability. A series of axisymmetric magneto-hydrodynamical simulations with detailed…

High Energy Astrophysical Phenomena · Physics 2017-02-16 Nobuya Nishimura , Hidetomo Sawai , Tomoya Takiwaki , Shoichi Yamada , Friedrich-Karl Thielemann

We have calculated microscopically bulk viscosity of hadronic matter, where equilibrium thermodynamics for all hadrons in medium are described by Hadron Resonance Gas (HRG) model. Considering pions and nucleons as abundant medium…

Nuclear Theory · Physics 2016-12-20 Sabyasachi Ghosh , Sandeep Chatterjee , Bedangdas Mohanty

Using numerical simulations based on solving the general relativistic hydrodynamic equations, we study the dynamics of a phase transition in the dense core of isolated rotating neutron stars, triggered by the back bending instability…

Solar and Stellar Astrophysics · Physics 2015-05-13 Harald Dimmelmeier , Michal Bejger , Pawel Haensel , J. Leszek Zdunik

We consider transport properties of the hypernuclear matter in neutron star cores. In particular, we calculate the thermal conductivity, the shear viscosity, and the momentum transfer rates for np$\Sigma^{-}\Lambda e\mu$ composition of…

High Energy Astrophysical Phenomena · Physics 2021-06-24 Peter Shternin , Isaac Vidaña

We study the dynamical evolution of the gravitational-wave driven instability of the f-mode in rapidly rotating relativistic stars. With an approach based on linear perturbation theory we describe the evolution of the mode amplitude and…

Solar and Stellar Astrophysics · Physics 2015-06-11 A. Passamonti , E. Gaertig , K. D. Kokkotas. D. Doneva

Hydrodynamic simulations of neutron star mergers rely on the clear separation between the strong-interaction, weak-interaction, and hydrodynamic timescales. In this effective framework, weak Urca interactions are typically the slowest…

High Energy Astrophysical Phenomena · Physics 2026-03-17 Jamie M. Karthein , Maneesha Sushama Pradeep , Rachel Steinhorst

The instability of r-mode oscillations in rapidly rotating neutron stars has attracted attention as a potential mechanism for producing high frequency, almost periodic gravitational waves. The analyses carried so far have shown the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Luciano Rezzolla , Frederick L. Lamb , Dragoljub Markovic , Stuart L. Shapiro

In this work, masses and radii of neutron stars are considered to investigate the effect of nuclear symmetry energy to the astrophysical observables. A relativistic mean field model with density-dependent meson-baryon coupling constants is…

Nuclear Theory · Physics 2015-05-30 Chung-Yeol Ryu , Chang Ho Hyun , Chang-Hwan Lee

We calculate the spectrum of inertial oscillation modes in a slowly rotating superfluid neutron star, including, for the first time, both the effects of finite temperatures and entrainment between superfluid neutrons and protons. We work in…

High Energy Astrophysical Phenomena · Physics 2018-11-07 Vasiliy A. Dommes , Elena M. Kantor , Mikhail E. Gusakov

We investigate the radial stability of neutron stars under conditions where their composition may or may not remain in chemical equilibrium during oscillations. Using different equations of state that include nucleons, hyperons, and/or…

High Energy Astrophysical Phenomena · Physics 2024-12-31 Martin O. Canullan-Pascual , German Lugones , Milva G. Orsaria , Ignacio F. Ranea-Sandoval

We consider the local dynamics of a realistic neutron star core, including composition gradients, superfluidity and thermal effects. The main focus is on the gravity g-modes, which are supported by composition stratification and thermal…

Solar and Stellar Astrophysics · Physics 2015-04-29 A. Passamonti , N. Andersson , W. C. G. Ho

We derive the hydrodynamical equations of r-mode oscillations in neutron stars in presence of a novel damping mechanism related to particle number changing processes. The change in the number densities of the various species leads to new…

High Energy Physics - Phenomenology · Physics 2013-04-30 Giuseppe Colucci , Massimo Mannarelli , Cristina Manuel

In this work I briefly review some of the effects of hyperons on the properties of neutron and proto-neutron stars. In particular, I revise the problem of the strong softening of the EoS, and the consequent reduction of the maximum mass,…

Nuclear Theory · Physics 2016-02-17 Isaac Vidana

Here we investigate the axial w quasi-normal modes of neutron stars for several equations of state. In particular, we study the influence of the presence of hyperons in the core of the neutron stars. We have obtained that w-modes can be…

General Relativity and Quantum Cosmology · Physics 2013-07-04 J. L. Blázquez-Salcedo , L. M. González-Romero , F. Navarro-Lérida

The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of…

Astrophysics · Physics 2008-11-26 M. Arnould , S. Goriely , K. Takahashi

The dynamical instability of new-born neutron stars is studied by evolving the linearized hydrodynamical equations. The neutron stars considered in this paper are those produced by the accretion induced collapse of rigidly rotating white…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Yuk Tung Liu

We derive the bulk viscous time scale of neutron stars with quark matter core, i.e. hybrid stars. The r-mode instability windows of the stars show the theoretical result accords with the rapid rotation pulsar data. The fit gives a strong…

Astrophysics · Physics 2007-05-23 Zheng Xiaoping , Pan Nana , Yang Shuhua , Liu Xuewen , Kang Miao