Related papers: Self-consistent 2D models of fast rotating early-t…
We present the first stationary, axisymmetric neutron star models with meridional circulation in general relativity. For that purpose, we developed GRNS, a new code based on a fixed point iteration. We find a two-dimensional set of…
We investigate the nature of low T/W dynamical instabilities in differentially rotating stars by means of linear perturbation. Here, T and W represent rotational kinetic energy and the gravitational binding energy of the star. This is the…
Since their formation, stars slow down their rotation rates by the removal of angular momentum from their surfaces, e.g. via stellar winds. Despite the complexity of the processes involved, a traditional model, where the removal of angular…
Oscillation modes in fast-rotating stars can be split into several subclasses, each with their own properties. To date, seismology of these stars cannot rely on regular pattern analysis and scaling relations. However, recently there has…
Rotation plays a key role in stellar structure and its evolution. Through transport processes which induce rotational mixing of chemical species and the redistribution of angular momentum, internal stellar rotation influences the…
We wish to understand the processes that control the fluid flows of a gravitationally contracting and rotating star or giant planet. We consider a spherical shell containing an incompressible fluid that is slowly absorbed by the core so as…
When the core hydrogen is exhausted during stellar evolution, the central region of a star contracts and the outer envelope expands and cools, giving rise to a red giant, in which convection occupies a large fraction of the star.…
Stellar evolution models of massive stars are very sensitive to the adopted mass-loss scheme. The magnitude and evolution of mass-loss rates significantly affect the main sequence evolution, and the properties of post-main sequence objects,…
We present an asymptotic theory that describes regular frequency spacings of pressure modes in rapidly rotating stars. We use an asymptotic method based on an approximate solution of the pressure wave equation constructed from a stable…
Observations of galaxy isophotes, longs-slit kinematics and high-resolution photometry suggested a possible dichotomy between two distinct classes of E galaxies. But these methods are expensive for large galaxy samples. Instead,…
Oscillation modes of a mixed character are able to probe the inner region of evolved low-mass stars and offer access to a range of information, in particular, the mean core rotation. Ensemble asteroseismology observations are then able to…
General-relativistic equilibria of differentially rotating stars are expected in a number of astrophysical scenarios, from core-collapse supernovae to the remnant of binary neutron-star mergers. The latter, in particular, have been the…
Next-generation gravitational wave detectors are expected to increase their sensitivity in the kHz band where binary neutron star remnants are expected to emit. In this context, robust predictions of oscillation modes of the post-merger…
We develop a formalism to model slowly rotating superfluid Newtonian neutron stars. A two-fluid model is used to describe the matter, where one fluid is the superfluid neutrons that are believed to exist in the inner crust and core of…
We have developed a new formulation to obtain self-gravitating, axisymmetric configurations in permanent rotation. The formulation is based on the Lagrangian variational principle with a triangulated mesh. It treats not only barotropic but…
We construct the first dynamically stable ergostars (equilibrium neutron stars that contain an ergoregion) for a compressible, causal equation of state. We demonstrate their stability by evolving both strict and perturbed equilibrium…
We investigate the evolution of rigidly and differentially rotating protoneutron stars (PNSs) during the first twenty seconds of their life. We solve the equations describing stationary axisymmetric configurations in general relativity…
The r-mode instability in rotating relativistic stars has been shown recently to have important astrophysical implications (including the emission of detectable gravitational radiation, the explanation of the initial spins of young neutron…
We present the results of 3--D simulations of core convection within A-type stars of 2 solar masses, at a range of rotation rates. We consider the inner 30% by radius of such stars, thereby encompassing the convective core and some of the…
We investigate baroclinic instability in flow conditions relevant to hot extrasolar planets. The instability is important for transporting and mixing heat, as well as for influencing large-scale variability on the planets. Both linear…