Related papers: Evolution of binary seeds in collapsing protostell…
Supermassive primordial stars forming in atomically-cooled halos at $z \sim15-20$ are currently thought to be the progenitors of the earliest quasars in the Universe. In this picture, the star evolves under accretion rates of $0.1 - 1$…
The fraction of stars in binary systems within star clusters is important for their evolution, but what proportion of binaries form by dynamical processes after initial stellar accretion remains unknown. In previous work, we showed that…
Previous high resolution cosmological simulations predict the first stars to appear in the early universe to be very massive and to form in isolation. Here we discuss a cosmological simulation in which the central 50 solar mass clump breaks…
Disk material has been observed around both components of some young close binary star systems. It has been shown that if planets form at the right places within such disks, they can remain dynamically stable for very long times. Herein, we…
We present the first three-dimensional gas-dynamical simulations of the grazing envelope evolution (GEE) of stars, with the goal of exploring the basic flow properties and the role of jets at the onset of the GEE. In the simulated runs, a…
We present the results of hydrodynamic simulations of the formation and subsequent orbital evolution of giant planets embedded in a circumbinary disc. We assume that a 20 earth masses core has migrated to the edge of the inner cavity formed…
We present general relativistic magnetohydrodynamic simulations of merging equal-mass, spinning black holes embedded in an equatorial thin slab of magnetized gas. We evolve black holes either non-spinning, with spins aligned to the orbital…
The formation of massive black hole binaries (MBHBs) is an unavoidable outcome of galaxy evolution via successive mergers. However, the mechanism that drives their orbital evolution from parsec separations down to the gravitational wave…
Using 3D radiation-hydrodynamic simulations and analytic theory, we study the orbital evolution of asymptotic-giant-branch (AGB) binary systems for various initial orbital separations and mass ratios, and thus different initial accretion…
The first directly detected gravitational waves (GW 150914) were emitted by two coalescing black holes (BHs) with masses of ~36Msun and ~29Msun. Several scenarios have been proposed to put this detection into an astrophysical context. The…
The majority of massive stars reside in binary systems, which are expected to experience mass transfer during their evolution. However, so far the conditions under which mass transfer leads to a common envelope, and thus possibly to a…
We present the results of non linear, hydrodynamic simulations, in three dimensions, of the tidal perturbation of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc mid-plane. The…
We use N-body simulations to study the dynamical evolution of Population III (Pop III) stellar systems and the resulting binary statistics. We design a physically-motivated framework for the initial conditions of Pop III star clusters,…
We present three-dimensional local hydrodynamic simulations of flows around objects embedded within stellar envelopes using a "wind tunnel" formalism. Our simulations model the common envelope dynamical inspiral phase in binary star systems…
We compute the isotropic gravitational wave (GW) background produced by binary supermassive black holes (SBHs) in galactic nuclei. In our model, massive binaries evolve at early times via gravitational-slingshot interaction with nearby…
Rapidly accreting massive protostars undergo a phase of deuterium shell burning during pre-main sequence evolution that causes them to swell to tenths of an AU in radius. During this phase, those with close binary companions will overflow…
Understanding the collapse of dense molecular cloud cores to stellar densities and the subsequent evolution of the protostar is of importance to model the feedback effects such an object has on its surrounding environment, as well as…
Linear analysis of gas flows around orbiting binaries suggests that a centrifugal barrier ought to clear a low-density cavity around the binary and inhibit mass transfer onto it. Modern hydrodynamics simulations have confirmed the…
We use the binary module of the MESA code to study the evolution of an evolved binary system where we assume that a main sequence companion removes the outskirts of the envelope of an asymptotic giant branch (AGB) star by launching jets,…
Binary systems are very common among field stars. While this relatively small number of planets in binaries is probably partly due to strong observational biases, there is, however, statistical evidence that planets are indeed less frequent…