Related papers: Constraining white-dwarf kicks in globular cluster…
Observations of white dwarfs in the globular clusters NGC 6397 and Omega Centauri indicate that these stars may get a velocity kick during their time as giants. If the mass loss while on the asymptotic giant branch is slightly asymmetric,…
If the winds of an asymptotic-giant-branch stars are sufficiently strong are slightly asymmetric, they can alter the star's trajectory through a globular cluster; therefore, if these winds are asymmetric, one would expect young white dwarfs…
Recent observations of white dwarfs in globular clusters indicate that these stars may get a velocity kick during their time as giants. This velocity kick could originate naturally if the mass loss while on the asymptotic giant branch is…
The wind of an asymptotic-giant-branch stars is sufficiently strong that if it is slightly asymmetric, it can propel the star outside of the open cluster of its birth or significantly alter its trajectory through a globular cluster;…
Recent observations of the white dwarf (WD) populations in the Galactic globular cluster NGC 6397 suggest that WDs receive a kick of a few km/s shortly before they are born. Using our Monte Carlo cluster evolution code, which includes…
Several lines of observational evidence suggest that white dwarfs receive small birth kicks due to anisotropic mass loss. If other stars possess extrasolar analogues to the Solar Oort cloud, the orbits of comets in such clouds will be…
We consider here the collective accretion of gas by globular clusters and dwarf galaxies moving through the interstellar medium. In the limit of high velocity and/or sound speed of the ISM, the collective potential of the cluster is…
We review empirical and theoretical findings concerning white dwarfs in Galactic globular clusters. Since their detection is a critical issue we describe in detail the various efforts to find white dwarfs in globular clusters. We then…
I will start by discussing the evolutionary status of the white dwarf *progenitors*, the hot UV bright stars. Observations of UIT-selected UV bright stars in globular clusters suggest that a high percentage of them manage to evolve from the…
We present a framework that explains the commonly observed variation in light element abundances in globular clusters. If globular clusters form in the centres of dwarf galaxies, they will be pumped onto larger orbits as star formation…
Globular clusters are ideal laboratories to study the evolution of low-mass stars. In this work we concentrate on three types of hot stars observed in globular clusters: horizontal branch stars, UV bright stars, and white dwarfs. After…
Observations of early-type dwarf galaxies in clusters often show that cluster dwarf members have significantly higher velocities and less symmetric distributions than cluster giant ellipticals, suggesting that these dwarfs are recently…
In Galactic open clusters, there is an apparent paucity of white dwarfs compared to the number expected assuming a reasonable initial mass function and that main-sequence stars with initial mass <= 8 M_sun become white dwarfs. We suggest…
We perform N-body simulations of a cluster that forms in a dwarf galaxy and is then accreted by the Milky Way to investigate how a cluster's structure is affected by a galaxy merger. We find that the cluster's half mass radius will respond…
We have examined the radial distribution of white dwarfs over a single HST/ACS field in the nearby globular cluster NGC 6397. In relaxed populations, such as in a globular cluster, stellar velocity dispersion, and hence radial distribution,…
The mere existence of multiple stellar generations in Milky Way globular clusters indicates that each generation was unable to stop star formation, that instead persisted unimpeded for several million years. This evidence argues for an…
We investigate the effect that dwarf galaxies have on the orbits, tidal histories, and assumed formation environment of Milky Way globular clusters. We determine the orbits of the Milky Way's 150 globular clusters in a gravitational…
Observations and theory both suggest that star clusters form sub-virial (cool) with highly sub-structured distributions. We perform a large ensemble of N-body simulations of moderate-sized (N=1000) cool, fractal clusters to investigate…
We show that kicks generated by topological currents may be responsible for the large velocities seen in a number of pulsars. The majority of the kick builds up within the first second of the star's birth and generates a force about two…
The maximum mass of a star that can produce a white dwarf (WD) is an important astrophysical quantity. One of the best approaches to establishing this limit is to search for WDs in young star clusters in which only massive stars have had…