Related papers: Accretion rates in hierarchical triple systems wit…
The standard picture of accretion is a steady flow of matter from the disc onto the young star - a concept which assumes the star-disc system to be completely isolated. However, in a dense cluster environment star-disc systems do interact…
We study the basic properties of accretion flows onto binary supermassive black holes, including the cases in which a circumbinary disk is misaligned with the binary orbital plane, by means of three-dimensional Smoothed Particle…
We demonstrate that gas disks around binary systems might deliver gas to the binary components only when the circumbinary disk is relatively warm. We present new grid-based hydrodynamics simulations, performed with the binary on the grid…
Mass transfer from an evolved donor star to its binary companion is a standard feature of stellar evolution in binaries. In wide binaries, the companion star captures some of the mass ejected in a wind by the primary star. The captured…
Triple stellar systems allow us to study stellar processes that cannot be attained in binary stars. The evolutionary phases in which the stellar members undergo mass exchanges can alter the hierarchical layout of these systems. Yet, the…
We report the findings of a comprehensive study of disk accretion and related phenomena in four of the nearest young stellar associations spanning 6-30 million years in age, an epoch that may coincide with the late stages of planet…
We report on simulations in general relativity of magnetized disks onto black hole binaries. We vary the binary mass ratio from 1:1 to 1:10 and evolve the systems when they orbit near the binary-disk decoupling radius. We compare (surface)…
Binary systems consisting of a secondary accreting form a wind-emitting primary are ubiquitous in astrophysics. The phenomenology of such Bondi-Hoyle-Lyttleton (BHL) accretors is particularly rich when an accretion disc forms around the…
Mass-transfer interactions in binary stars can lead to accretion disk formation, mass loss from the system and spin-up of the accretor. To determine the trajectory of the mass-transfer stream, and whether it directly impacts the accretor,…
Classical T Tauri stars (CTTSs) are young stellar objects that accrete materials from their accretion disc influenced by their strong magnetic field. The magnetic pressure truncates the disc at a few stellar radii and forces the material to…
We review the present knowledge of disk accretion in young low mass stars, and in particular, the mass accretion rate and its evolution with time. The methods used to obtain mass accretion rates from ultraviolet excesses and emission lines…
Young stars show evidence of accretion discs which evolve quickly and disperse with an e-folding time of $\sim$ 3Myr. This is in striking contrast with recent observations that suggest evidence for numerous $>30$ Myr old stars with an…
Accretion rates of order 10^-8 M_\odot/yr are observed in young protostars of approximately a solar mass with evidence of circumstellar disks. The accretion rate is significantly lower for protostars of smaller mass, approximately…
So far, stellar population studies have mainly focused on the evolution of single and binary stars. Recent observations show that triple and higher order multiple star systems are common, especially among massive stars. Introducing…
Most massive stars are born in binaries close enough for mass transfer episodes. These modify the appearance, structure, and future evolution of both stars. We compute the evolution of a 100-day period binary consisting initially of a 25 M…
Young stars and planetary systems form in molecular clouds. For classical T Tauri stars (CTTS, F-K type precursors) the accretion disk does not reach down to the central star, but it is truncated near the co-rotation radius. The inner edge…
When an accretion disk surrounds a binary rotating in the same sense, the binary exerts strong torques on the gas. Analytic work in the 1D approximation indicated that these torques sharply diminish or even eliminate accretion from the disk…
We carry out a numerical experiment of ejecting winds in a massive colliding wind binary system, and quantifying the accretion onto the secondary star under different primary mass loss rates. We set a binary system comprising a Luminous…
We present a suite of high resolution hydrodynamic simulations of binaries immersed in circumbinary accretion disks (CBDs). For the first time, we investigate the preferential accretion rate as a function of both eccentricity $e_{\rm b}$…
The surroundings of massive protostars constitute an accretion disc which has numerically been shown to be subject to fragmentation and responsible for luminous accretion-driven outbursts. Moreover, it is suspected to produce close binary…