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Related papers: Stable Hydrogen burning limits in rapidly rotating…

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We revisit secular stability against quasi-radial collapse for rigidly rotating supermassive stars (SMSs) in general relativity. We suppose that the SMSs are in a nuclear-burning phase and can be modeled by polytropic equations of state…

High Energy Astrophysical Phenomena · Physics 2016-04-13 Masaru Shibata , Haruki Uchida , Yuichiro Sekiguchi

We explore a possible scenario of the explosion as a result of core collapses of rotating massive stars that leave a black hole by performing a radiation-viscous-hydrodynamics simulation in numerical relativity. We take moderately and…

High Energy Astrophysical Phenomena · Physics 2023-09-06 Sho Fujibayashi , Yuichiro Sekiguchi , Masaru Shibata , Shinya Wanajo

We consider hot, two-temperature, viscous accretion onto a rotating, unmagnetized neutron star. We assume Coulomb coupling betweenthe protons and electrons, and free-free cooling from the electrons. We show that the accretion flow has an…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev , Ramesh Narayan

We consider combined rotational, magnetic, and thermal evolution of the neutron star during the accretion phase in a binary system. A rapid accretion-driven decay of the magnetic field decreases substantially the efficiency of angular…

High Energy Astrophysical Phenomena · Physics 2015-07-14 Alfio Bonanno , Vadim Urpin

We discuss the stability and construct dynamical configurations describing the gravitational collapse of unstable neutron stars with realistic equations of state compatible with the recent LIGO-Virgo constraints. Unlike other works that…

General Relativity and Quantum Cosmology · Physics 2020-06-17 J. M. Z. Pretel , M. F. A. da Silva

Asteroseismic measurements of the internal rotation rate in evolved stars pointed out to a lack of angular momentum (AM) transport in stellar evolution models. Several physical processes in addition to hydrodynamical ones were proposed as…

Solar and Stellar Astrophysics · Physics 2023-05-17 F. D. Moyano , P. Eggenberger , B. Mosser , F. Spada

Angular momentum evolution in low-mass stars is determined by initial conditions during star formation, stellar structure evolution, and the behaviour of stellar magnetic fields. Here we show that the empirical picture of angular momentum…

Solar and Stellar Astrophysics · Physics 2015-06-03 Ansgar Reiners , Subhanjoy Mohanty

We describe a phenomenological model for molecular hydrogen formation suited for applications in galaxy formation simulations, which includes on-equilibrium formation of molecular hydrogen on dust and approximate treatment of both its…

Astrophysics · Physics 2010-12-28 Nickolay Y. Gnedin , Konstantinos Tassis , Andrey V. Kravtsov

We investigate the impact of stellar rotation on the formation of black holes (BHs), by means of our population-synthesis code SEVN. Rotation affects the mass function of BHs in several ways. In massive metal-poor stars, fast rotation…

High Energy Astrophysical Phenomena · Physics 2020-03-20 Michela Mapelli , Mario Spera , Enrico Montanari , Marco Limongi , Alessandro Chieffi , Nicola Giacobbo , Alessandro Bressan , Yann Bouffanais

We numerically calculate equilibrium configurations of uniformly rotating and charged neutron stars, in the case of insulating material and neglecting the electromagnetic forces acting on the equilibrium of the fluid. This allows us to…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Jerome Novak , Emmanuel Marcq

The lower bound on the period of uniform rotation of neutron stars (NS) with causal equation of state (EOS), P_ min, is shown to be determined, with a high precision, by the upper bound on the surface redshift of static neutron star models,…

Astrophysics · Physics 2007-05-23 P. Haensel , J. P. Lasota , J. L. Zdunik

A rotating star may be modeled as a continuous system of particles attracted to each other by gravity and with a given total mass and prescribed angular velocity. Mathematically this leads to the Euler-Poisson system. We prove an existence…

Analysis of PDEs · Mathematics 2018-04-17 Yilun Wu , Walter Strauss

The effects of gravitational settling and radiative levitation in the stellar atmospheres and envelopes of subdwarf B (sdB) stars strongly depend on the presence of weak winds. In the paper the existence of weak radiatively driven winds is…

Astrophysics · Physics 2008-07-10 Klaus Unglaub

We have obtained CO(J=2-1) spectra of nine face-on low surface brightness galaxies(LSBGs) using the JCMT 15-meter telescope and observed Ha images using the 2.16-meter telescope of NAOC. As no CO has been detected, only upper limits on the…

The relativistic hydrodynamics equations are adapted for the spherically symmetric case and the Lagrangian form. They are used to model the explosive disruption of a minimum-mass neutron star: a key ingredient of the stripping model for…

High Energy Astrophysical Phenomena · Physics 2022-08-26 A. V. Yudin

We have used the upgraded Giant Metrewave Radio Telescope to carry out a deep (117 on-source hours) L-band observation of the Extended Groth Strip, to measure the average neutral hydrogen (HI) mass and median star formation rate (SFR) of…

Astrophysics of Galaxies · Physics 2019-09-16 Apurba Bera , Nissim Kanekar , Jayaram N. Chengalur , Jasjeet S. Bagla

Present time-domain astronomy efforts will unveil a variety of rare transients. We focus here on pulsational pair-instability evolution, which can result in signatures observable with electromagnetic and gravitational waves. We simulate…

Solar and Stellar Astrophysics · Physics 2020-08-19 M. Renzo , R. Farmer , S. Justham , Y. Götberg , S. E. de Mink , E. Zapartas , P. Marchant , N. Smith

I review our understanding of the thermonuclear instabilities on accreting neutron stars that produce Type I X-Ray bursts. I emphasize those observational and theoretical aspects that should interest the broad audience of this meeting. The…

Astrophysics · Physics 2009-10-31 Lars Bildsten

N-body dynamical simulations are used to analyze the conditions for the gravitational stability of a three-dimensional stellar disk in the gravitational field of two rigid spherical components--a bulge and a halo whose central…

Astrophysics · Physics 2009-11-07 A. V. Khoperskov , A. V. Zasov , N. V. Tyurina

We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by…

Solar and Stellar Astrophysics · Physics 2015-05-13 P. D. Klaassen , C. D. Wilson , E. R. Keto , Q. Zhang