Related papers: High-resolution simulations of stellar collisions …
We explore the evolution of collisionally merged stars in the blue straggler region of the HR diagram. The starting models for our stellar evolution calculations are the results of the smoothed particle hydrodynamics (SPH) simulations of…
Stellar collisions are an important formation channel for blue straggler stars in globular and old open clusters. Hydrodynamical simulations have shown that the remnants of such collisions are out of thermal equilibrium, are not strongly…
We continue our exploration of collisionally merged stars in the blue straggler region of the color-magnitude diagram. We report the results of new SPH calculations of parabolic collisions between two main-sequence stars, with the initial…
Collisions of main sequence stars occur frequently in dense star clusters. In open and globular clusters, these collisions produce merger remnants that may be observed as blue stragglers. Detailed theoretical models of this process require…
We report the results of new SPH calculations of parabolic collisions between two main-sequence stars in a globular cluster. Such collisions are directly relevant to the formation of blue stragglers. In particular, we consider parent stars…
In young dense clusters repeated collisions between massive stars may lead to the formation of a very massive star (above 100 Msun). In the past the study of the long-term evolution of merger remnants has mostly focussed on collisions…
We investigate the structure and evolution of blue stragglers stars which were formed from direct stellar collisions between main sequence stars in globular clusters. In particular, we look at the rotational evolution of the products of…
The evolution of stellar collision products in cluster simulations has usually been modelled using simplified prescriptions. Such prescriptions either replace the collision product with an (evolved) main sequence star, or assume that the…
Star cluster formation in giant molecular clouds involves the local collapse of the cloud into small gas-rich subclusters, which can then subsequently collide and merge to build up the final star cluster(s). In this paper, we simulate…
Blue straggler stars (BSS) are abundantly observed in all Galactic globular clusters (GGC) where data exist. However, observations alone cannot reveal the relative importance of various formation channels or the typical formation times for…
In a companion paper we studied the detailed evolution of stellar collision products that occurred in an $N$-body simulation of the old open cluster M67 and compared our detailed models to simple prescriptions. In this paper we extend this…
Blue straggler stars in stellar clusters are a subset of stars that are bluer and appear younger than other cluster members, seemingly straggling behind in their evolution. They offer a unique opportunity to understand the stellar dynamics…
We investigate the evolution of collisionally merged stars with mass of ~100 MSun which might be formed in dense star clusters. We assumed that massive stars with several tens Msun collide typically after ~1Myr of the formation of the…
We study the effects of stellar collisions, particularly on feeding massive black holes (BHs) and color gradients, in realistic galactic centers. We find that the mass released by stellar collisions is not sufficient to account for the…
We present an analysis of optical HST/STIS and HST/FOS spectroscopy of 6 blue stragglers found in the globular clusters M3, NGC6752 and NGC6397. These stars are a subsample of a set of ~50 blue stragglers and stars above the main sequence…
We report the results of new SPH calculations of parabolic collisions between main-sequence (MS) stars. The stars are assumed to be close to the MS turn-off point in a globular cluster and are therefore modeled as $n=3$, $\Gamma=5/3$…
Blue stragglers in globular clusters are abnormally massive stars that should have evolved off the stellar main sequence long ago. There are two known processes that can create these objects: direct stellar collisions and binary evolution.…
In young star clusters, the density can be high enough and the velocity dispersion low enough for stars to collide and merge with a significant probability. This has been suggested as a possible way to build up the high-mass portion of the…
Globular clusters should be born with significant numbers of stellar-mass black holes (BHs). It has been thought for two decades that very few of these BHs could be retained through the cluster lifetime. With masses ~10 MSun, BHs are ~20…
We study the post-main sequence evolution of products of collisions between main sequence stars (blue stragglers), with particular interest paid to the horizontal branch and asymptotic giant branch phases. We found that the blue straggler…