Related papers: Building Blue Stragglers with Stellar Collisions
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…
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…
This chapter describes the current state of models of individual blue stragglers. Stellar collisions, binary mergers (or coalescence), and partial or ongoing mass transfer have all been studied in some detail. The products of stellar…
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…
A primary production mechanism for blue stragglers in globular clusters is thought to be collisionally-induced mergers, perhaps mediated by dynamical encounters involving binary stars. We model the formation and evolution of such blue…
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…
The hydrodynamics of stellar collisions and mergers is discussed in the context of blue straggler formation. Emphasis is placed on the very important question of hydrodynamic mixing during the merger process. Recent results of…
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…
We created artificial color-magnitude diagrams of Monte Carlo dynamical models of globular clusters, and then used observational methods to determine the number of blue stragglers in those clusters. We compared these blue stragglers to…
We review recent 3D hydrodynamic calculations of stellar collisions using the Smoothed Particle Hydrodynamics (SPH) method, and we discuss the implications of the results for the formation and evolution of blue stragglers in globular…
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…
When two stars collide and merge they form a new star that can stand out against the background population in a starcluster as a blue straggler. In so called collision runaways many stars can merge and may form a very massive star that…
We use smoothed-particle hydrodynamics to examine differences between direct collisions of single stars and binary star mergers in their roles as possible blue straggler star formation mechanisms. We find in all cases that core helium in…
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…
We performed high-resolution simulations of two stellar collisions relevant for stars in globular clusters. We considered one head-on collision and one off-axis collision between two 0.6 M_sun main sequence stars. We show that a resolution…
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.…
Blue stragglers are natural phenomena in star clusters. They originate through mass transfer in isolated binaries, as well as through encounters between two or more stars, in a complex interplay between stellar dynamics and stellar…
The hydrodynamics of collisions and mergers of main-sequence stars is discussed in the light of recent 3-D calculations using the smoothed particle hydrodynamics (SPH) method. Theoretical models for the formation of blue stragglers are…
We have used the results of recent smoothed particle hydrodynamic simulations of colliding stars to create models appropriate for input into a stellar evolution code. In evolving these models, we find that little or no surface convection…