Related papers: Extending Common Envelope Simulations from Roche L…
We explore the three-dimensional properties of convective, luminous ($L\approx10^{4.5}-10^{5}L_\odot$), Hydrogen-rich envelopes of Red Supergiants (RSGs) based on radiation hydrodynamic simulations in spherical geometry using…
We use a Monte Carlo code to generate synthetic near-IR reflection nebulae that resemble those (normally associated with a bipolar outflow cavity) seen towards massive young stellar objects (YSOs). The 2D axi-symmetric calculations use an…
Three-dimensional simulations usually fail to cover the entire dynamical common-envelope phase of gravitational wave progenitor systems due to the vast range of spatial and temporal scales involved. We investigated the common-envelope…
We present a suite of dynamical simulations designed to explore the orbital and accretion properties of compact (2$-$7 AU) symbiotic systems, focusing on wind accretion, drag forces, and tidal interactions. Using three levels of physical…
Tidal dissipation due to turbulent viscosity in the convective regions of giant stars plays an important role in shaping the orbits of pre-common envelope systems. Such systems are possible sources of transients and close compact binary…
We describe a new code to simulate the stellar evolution of a close interacting binary system. It is then used to calculate the evolution of a classical nova system composed of a 1.25 Msun Main-Sequence (MS) star and a 1.0 Msun white dwarf…
Common envelope (CE) evolution is a critical but still poorly understood progenitor phase of many high-energy astrophysical phenomena. Although 3D global hydrodynamic CE simulations have become more common in recent years, those involving…
Several observational pieces of evidence indicate that specific evolutionary channels which involve Roche lobe overflow are not correctly accounted for by the classical Roche model. We generalize the concept of Roche lobe in the presence of…
Through tidal dissipation in a slowly spinning host star the orbits of many hot Jupiters may decay down to the Roche limit. We expect that in most cases the ensuing mass transfer will be stable. Using detailed numerical calculations we find…
We discuss the evolution of binaries with moderately high masses (about 10 - 30 solar masses), and with periods of about 3 - 300d, corresponding mostly to early Case B. These are usually thought to evolve either by reasonably conservative…
We present a comparative study between the results of most hydrodynamic simulations of the common envelope binary interaction to date and observations of post common envelope binaries. The goal is to evaluate whether this dataset indicates…
Cygnus~X-3 is a Galactic X-ray binary with a 4.8-hr orbital period operating in the ultraluminous regime. Although the system is viewed at relatively low inclination ($i\approx28^\circ$), it exhibits a deep orbital modulation. Recent IXPE…
Close-binary evolution couples Roche-lobe overflow (RLOF), common-envelope (CE) drag, stellar winds, magnetic braking, and gravitational-wave losses, exchanging mass and angular momentum while reshaping orbits and spins. We present…
The evolution of triples has not attracted much attention in the literature, although their evolution can be dramatically different from binaries and single stars. Triples are quite common, and we find that for about 1% of the triples in…
We present the first calculations of mass transfer via RLOF for a binary system with a significant eccentricity using our new binary stellar evolution code. The study focuses on a 1.50+1.40 Msun main sequence binary with an eccentricity of…
Modeling the evolution of progenitors of gravitational-wave merger events in binary stars faces two major uncertainties: the common-envelope phase and supernova kicks. These two processes are critical for the final orbital configuration of…
We study the merging of massive stars inside a common envelope for binary systems consisting of a red supergiant with a mass of 15-20 Msun and a main-sequence companion of 1-5 Msun. We are particularly interested in the stage when the…
We perform 3D hydrodynamical simulations to study recombination and ionization during the common envelope (CE) phase of binary evolution, and develop techniques to track the ionic transitions in time and space. We simulate the interaction…
We present 3D radiation hydrodynamics simulations of common-envelope (CE) evolution involving a 12 solar mass red supergiant donor and a 3 solar mass companion. Existing 3D simulations are predominantly adiabatic, focusing strongly on…
Supergiant fast X-ray transients (SFXTs) are X-ray binary systems with a supergiant companion and likely a neutron star, which show a fast ($\sim 10^3$ s) and high variability with a dynamic range up to $10^{5-6}$. Given their extreme…