Related papers: Structure and evolution of high-mass stellar merge…
We study the evolution and fate of solar composition supermassive stars in the mass range 60 - 1000 Msun. Our study is relevant both for very massive objects observed in young stellar complexes as well as supermassive stars that may…
Dense core collisions, previously regarded as minor in star formation, are proposed to play a significant role in structure formation around protostellar envelopes and binary formation. Using archival data of nearby star-forming regions, we…
Theoretical modeling of massive stars predicts a gap in the black hole (BH) mass function above $\sim 40-50\,M_{\odot}$ for BHs formed through single star evolution, arising from (pulsational) pair-instability supernovae. However, in dense…
Dense star clusters are spectacular self-gravitating stellar systems in our Galaxy and across the Universe - in many respects. They populate disks and spheroids of galaxies as well as almost every galactic center. In massive elliptical…
Massive stars can develop into tepid supergiants at several stages of their post main-sequence evolution, prior to core He-burning, on a blue loop, or close to the final supernova explosion. We discuss observational constraints on models of…
The evolution of massive stars is affected by a variety of physical processes including convection, rotation, mass loss and binary interaction. Because these processes modify the internal chemical abundance profiles in multiple ways…
Interactions between massive stars in binaries are thought to be responsible for much of the observed diversity of supernovae. As surveys probe rarer populations of events, we should expect to see supernovae arising from increasingly…
Physical collisions between stars occur frequently in dense star clusters, either via close encounters between two single stars, or during strong dynamical interactions involving binary stars. Here we study stellar collisions that occur…
Like most galaxies, the Milky Way harbors a supermassive black hole (SMBH) at its center, surrounded by a nuclear star cluster. In this dense star cluster, direct collisions can occur between stars before they evolve off the main-sequence.…
We systematically study the effects of collisions on the overall dynamical evolution of dense star clusters using Monte Carlo simulations over many relaxation times. We derive many observable properties of these clusters, including their…
It is not known how single white dwarfs with masses less than 0.5Msolar -- low-mass white dwarfs -- are formed. One way in which such a white dwarf might be formed is after the merger of a helium-core white dwarf with a main-sequence star…
We study the shape and evolution of the star formation main sequence in three independently developed semi-analytic models of galaxy formation. We focus, in particular, on the characterization of the model galaxies that are significantly…
The star formation rate history of galactic objects in hydrodynamical cosmological simulations are analyzed in relation to their merger histories. The findings suggest that massive mergers produce more efficient starbursts and that,…
Mergers between helium white dwarfs and main-sequence stars are likely common, producing red giant-like remnants making up roughly a few percent of all low-mass ($\lesssim2M_\odot$) red giants. Through detailed modeling, we show that these…
Isolated hot subdwarfs might be formed by the merging of two helium-core white dwarfs. Before merging, helium-core white dwarfs have hydrogen-rich envelopes and some of this hydrogen may survive the merger. We calculate the mass of hydrogen…
We study the long-term evolution of two or more stellar black holes (BHs) on initially separated but unstable circular orbits around a supermassive BH (SMBH). Such a close-packed orbital configuration can naturally arise from BH migrations…
The evolution of helium stars with initial masses in the range 1.6 to 120 Msun is studied, including the effects of mass loss by winds. These stars are assumed to form in binary systems when their expanding hydrogenic envelopes are promptly…
We propose that there is an evolutionary link between ultra-compact blue dwarf galaxies (UCBDs) with active star formation and nucleated dwarfs based on the results of numerical simulations of dwarf-dwarf merging. We consider the…
Galaxy mergers can enhance star formation rates throughout the merger sequence, with this effect peaking around the time of coalescence. However, owing to a lack of information about their time of coalescence, post-mergers could only…
We summarize the results of numerical simulations of colliding gas-rich disk galaxies in which the impact velocity is set parallel to the spin axes of the two galaxies. The effects of varying the impact speed are studied with particular…