Related papers: Unresolved binaries and Galactic clusters' mass es…
The effects which star cluster concentration and binarity have on observable parameters, that characterise the dynamical state of a population of stars after their birth aggregate dissolves, are investigated. To this end, the correlations…
Binary stars are predicted to have an important role in the evolution of globular clusters, so we obtained binary fractions for 35 globular clusters that were imaged in the F606W and F814W with the ACS on the Hubble Space Telescope. When…
Binaries play a critical role in the formation, evolution, and fundamental properties of planets, stars, and stellar associations. Observational studies in these areas often include a mix of observations aimed at detecting or ruling out the…
We analyze the currently available observations of X-ray binaries in a consistent way, to re-determine the masses of the neutron stars in these systems. In particular, our attention is focussed on a realistic and consistent assessment of…
The binary fraction of a stellar population can have pronounced effects on its properties, and in particular the number counts of different massive star types, and the relative subtype rates of the supernovae which end their lives. Here we…
Stellar mass black hole binaries have individual masses between 10-80 solar masses. These systems may emit gravitational waves at frequencies detectable at Megaparsec distances by space-based gravitational wave observatories. In a previous…
I discuss two of the possible sources of biases in the determination of the IMF: binning and the existence of unresolved components. The first source is important for clusters with a small number of stars detected in a given mass bin while…
Open clusters, which have age, abundance, and extinction information from studies of main-sequence turn off stars, are the ideal location in which to determine the mass-luminosity-radius relation for low-mass stars. We have undertaken a…
Using our new Binary Population and Spectral Synthesis (BPASS) code we explore the affect of binary populations on the integrated spectra of galaxies. We also explore the interplay of binary populations and a varying maximum stellar mass.…
While it is well known that mass transfer in binaries can pollute the surfaces of the accretors, it is still unclear whether this mechanism can reproduce the observed chemical inhomogeneities in globular clusters. We study the surface…
This paper is the fourth one of a series whose chief objective is studying the influence of different mass spectra on the dynamical evolution of open star clusters. Results from several N-body calculations with primordial binaries and mass…
We will discuss the evolution of star clusters with an large initial binary fraction, up to 95%. The initial binary population is chosen to follow the invariant orbital-parameter distributions suggested by Kroupa (1995). The Monte Carlo…
Observations indicate that the fraction of potential binary star clusters in the Magellanic Clouds is about 10%. In contrast, it is widely accepted that the binary cluster frequency in the Galaxy disk is much lower. Here we investigate the…
Most main sequence stars, unlike our Sun, belong to multiple systems with two or more stars. How and when these multiples come together and become bound is uncertain, since the earliest stages of star formation are difficult to resolve. We…
We have searched for visual binaries with projected separations in the range 200-3000 AU (0.1"-1.5") among a sample of 96 stars in the massive young NGC 6611 cluster, 60 of them being subsequently identified as high probability cluster…
Based on a set of over 100 medium- to high-resolution optical spectra collected from 2003 to 2009, we investigate the properties of the O-type star population in NGC6611 in the core of the Eagle Nebula (M16). Using a much more extended data…
Nearby companions alter the evolution of massive stars in binary systems. Using a sample of Galactic massive stars in nearby young clusters, we simultaneously measure all intrinsic binary characteristics relevant to quantify the frequency…
The apparent age and mass of a stellar cluster can be strongly affected by stochastic sampling of the stellar initial mass function, when inferred from the integrated color of low mass clusters (less than ~10^4 solar masses). We use…
We study the binary fraction of the globular cluster M10 (NGC 6254) as a function of radius from the cluster core to the outskirts, by means of a quan- titative analysis of the color distribution of stars relative to the fiducial main…
The recent discovery of GW150914, the binary black hole merger detected by Advanced LIGO, has the potential to revolutionize observational astrophysics. But to fully utilize this new window into the universe, we must compare these new…