Related papers: Simulating a binary system that experiences the gr…
I review the roles of jet-inflated bubbles in determining the evolution of different astrophysical objects. I discuss astrophysical systems where jets are known to inflate bubbles (cooling flow [CF] clusters; young galaxies; intermediate…
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…
It is now clear that central star binarity plays a key role in the formation and evolution of planetary nebulae, with a significant fraction playing host to close-binary central stars which have survived one or more common envelope…
The physical mechanism(s) responsible for transitioning from a spherical Asymptotic Giant Branch (AGB) star to an asymmetric post-AGB (pAGB) object is poorly understood. In particular, excess momenta in the outflows of pAGB objects suggest…
An approximate strategy for studying the evolution of binary systems of extended objects is introduced. The stars are assumed to be polytropic ellipsoids. The surfaces of constant density maintain their ellipsoidal shape during the time…
Bipolar expansion at various stages of evolution has been recently observed in a number of AGB stars. The expansion is driven by bipolar jets that emerge late in the evolution of AGB winds. The wind traps the jets, resulting in an…
Simulations of binary neutron stars have seen great advances in terms of physical detail and numerical quality. However, the spin of the neutron stars, one of the simplest global parameters of binaries, remains mostly unstudied. We present…
This paper is the second in a series investigating the evolution of star clusters towards energy equipartition (EEP). Here, we focus on the effects of the external tidal field of the host galaxy, initial anisotropy in the velocity…
We study the properties of jets launched by a neutron star spiralling inside the envelope and core of a red supergiant. We propose that Thorne-Zytkow objects (TZO) are unlikely to be formed via common envelope (CE) evolution if accretion on…
We study a novel electromagnetic signature of supermassive black hole binaries whose inspiral starts being dominated by gravitational wave (GW) emission. Recent simulations suggest that the binary's member BHs can continue to accrete gas…
The formation pathways for gravitational-wave merger sources are predicted to include common envelope (CE) evolution. Observations of high-mass post-common envelope binaries suggest that energy transfer to the envelope during the CE phase…
Relativistic jets launched in binary neutron star (BNS) mergers are widely accepted as the engines powering most of the population of short gamma-ray bursts (GRBs). Understanding their structure and dynamics-particularly during and after…
Binary systems of Population III can evolve to microquasars when one of the stars collapses into a black hole. When the compact object accretes matter at a rate greater than the Eddington rate, powerful jets and winds driven by strong…
It is believed that the relativistic jets of gamma-ray bursts (GRBs) should initially propagate through a heavy envelope of the massive progenitor stars or through a merger ejecta formed from the compact binary mergers. The interaction of a…
We investigate mass transfer and the formation of disc in binary systems using a combination of numerical simulations and theory. We consider six models distinguished by binary separation, secondary mass and outflow mechanisms. Each system…
The energy budget in common-envelope events (CEEs) is not well understood, with substantial uncertainty even over to what extent the recombination energy stored in ionised hydrogen and helium might be used to help envelope ejection. We…
As of today over 40 planetary systems have been discovered in binary star systems. In all cases the configuration appears to be circumstellar, where the planets orbit around one of the stars, the secondary acting as a perturber. The…
Gamma-ray bursts (GRBs) are produced during the propagation of ultra-relativistic jets. It is challenging to study the jet close to the central source, due to the high opacity of the medium. In this paper, we present numerical simulations…
In the current galaxy formation scenarios, two physical phenomena are invoked to build disk galaxies: hierarchical mergers and more quiescent external gas accretion, coming from intergalactic filaments. Although both are thought to play a…
A stellar common envelope occurs in a binary system when the atmosphere of an evolving star expands to encompass an orbiting companion object. Such systems are predicted to evolve rapidly, ejecting the stellar envelope and leaving the…