Related papers: A comparison of hydrodynamics techniques for model…
Mergers of two carbon-oxygen white dwarfs have long been suspected to be progenitors of Type Ia Supernovae. Here we present our modifications to the cosmological smoothed particle hydrodynamics code Gadget to apply it to stellar physics…
The onset of runaway stellar collisions in young star clusters is more likely to initiate with an encounter between a binary and a third star than between two single stars. Using the initial conditions of such three-star encounters from…
The Santa Barbara cluster comparison project (Frenk et al. Frenk+1999) revealed that there is a systematic difference between entropy profiles of clusters of galaxies obtained by Eulerian mesh and Lagrangian smoothed particle hydrodynamics…
Supermassive stars are Population III stars with masses exceeding $10^4\,M_{\odot}$ that could be the progenitors of the first supermassive black holes. Their interiors are in a regime where radiation pressure dominates the equation of…
The ambient hot intra-halo gas in clusters of galaxies is constantly fed and stirred by in-falling galaxies, a process that can be studied in detail with cosmological hydro- dynamical simulations. However, different numerical methods yield…
A new semi-analytical model of a star evolving in a tidal field is proposed. The model is a generalization of the so-called 'affine' stellar model. In our model the star is composed of elliptical shells with different parameters and…
We describe the theory and implementation of a three-dimensional fluid dynamics code which we have developed for calculating the surface geometry and circulation currents in the secondaries of interacting binary systems. The main method is…
The merger scenario of two galaxy subclusters to form the massive galaxy cluster 'El Gordo' is investigated using smoothed particle hydrodynamics (SPH) simulations. Idealized cluster models are used to initialize the states of both…
Contradicting results have been reported in the literature with respect to the performance of the numerical techniques employed for the study of supersonic turbulence. We aim at characterising the performance of different particle-based and…
(Abridged) In this paper we present a compilation of results from our most advanced neutron star merger simulations, including a description of the employed numerical procedures and a more complete overview over a large number of computed…
We review the numerical techniques for ideal and non-ideal magneto-hydrodynamics (MHD) used in the context of star formation simulations. We outline the specific challenges offered by modeling star forming environments, which are dominated…
We study the nucleosynthesis and the induced mixing during the merging of massive stars inside a common envelope. The systems of interest are close binaries, initially consisting of a massive red supergiant and a main-sequence companion of…
Particle tagging is an efficient, but approximate, technique for using cosmological N-body simulations to model the phase-space evolution of the stellar populations predicted, for example, by a semi-analytic model of galaxy formation. We…
We perform simulations of giant impacts onto the young Uranus using smoothed particle hydrodynamics (SPH) with over 100 million particles. This 100--1000$\times$ improvement in particle number reveals that simulations with below 10^7…
We present REMIX, a smoothed particle hydrodynamics (SPH) scheme designed to alleviate effects that typically suppress mixing and instability growth at density discontinuities in SPH simulations. We approach this problem by directly…
Spectra of late-type stars are usually analyzed with static model atmospheres in local thermodynamic equilibrium (LTE) and a homogeneous plane-parallel or spherically symmetric geometry. The energy balance requires particular attention, as…
To make relevant predictions about observable emission, hydrodynamical simulation codes must employ schemes that account for radiative losses, but the large dimensionality of accurate radiative transfer schemes is often prohibitive.…
Galaxy mergers have been investigated for decades using smoothed particle hydrodynamics (SPH), but recent work highlighting inaccuracies inherent in the traditional SPH technique calls into question the reliability of previous studies. We…
Most massive stars exchange mass with a companion, leading to evolution which is altered drastically from that expected of stars in isolation. Such systems are the result of unusual binary evolution pathways and, as such, may be used to…
Stellar collisions have long been envisioned to be of great importance in the center of galaxies where densities of 1e6 stars per cubic pc or higher are attained. Not only can they play a unique dynamical role by modifying stellar masses…