Topic
Mass segregation
About: Mass segregation is a research topic. Over the lifetime, 1024 publications have been published within this topic receiving 57729 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this paper, the authors used deep CCD images of the extremely young open star cluster NGC 6611, up to a limiting magnitude of V − 22.86 mag in V, R and I passbands.
2 citations
01 Jan 2018
TL;DR: In this paper, the authors investigate how the rate of star cluster formation affects its dynamical evolution, which is the first time such a study has been conducted for realistic clusters that have realistic binary properties, and carry out an example study of how the observed properties of a particular set of runaway stars can constrain properties of the dynamical ejection event.
Abstract: A major question in astrophysics is how star clusters form. These objects are important, since they are the birth sites of most stars, perhaps including our own Sun. There are different theoretical models of cluster formation and our main goal is to examine how they may affect the dynamical evolution of the stars in the system, including those stars that are ejected from the cluster. In particular, we set up cluster formation models with global initial conditions of the Turbulent Clump Model, which has been proposed as a description of gas structures within molecular clouds. We then investigate how global star formation efficiency from such a natal gas clump, overall clump density, degree of primordial mass segregation, degree of primordial binarity and binary population properties affect the subsequent dynamical evolution. In a second paper, after a major code development that allows modeling of gradual star formation, we investigate how the rate of star cluster formation affects its dynamical evolution, which is the first time such a study has been conducted for realistic clusters that have realistic binary properties. We show througth this thesis that star clusters that formed fast, i.e., during about one free-fall time, show quite different properties than star clusters that forms in a slow quasi-equilibirum fashion. Quickly-formed clusters tend to expand much faster compared to slow-formed clusters, thus requiring higher initial densities to agree with observations. Creation of the runaway stellar population is also sensitive to the rate of cluster formation. Future directions of this work, adding greater degrees of realism are also discussed. Finally, we carry out an example study of how the observed properties of a particular set of runaway stars can constrain properties of the dynamical ejection event, with implications for the closest region of massive star formation in the Orion Nebula Cluster.
2 citations
01 Jan 1989
TL;DR: In this article, color and population gradients in the cores of several highly concentrated globular clusters are reported, and the gradients are in the sense of blueing toward the cluster center, and appear to be caused mostly or entirely by population gradient in the number of blue horizontal branch and red giant branch stars.
Abstract: New observational results on color and population gradients in the cores of several highly concentrated globular clusters are reported. The gradients are in the sense of blueing toward the cluster center, and appear to be caused mostly or entirely by population gradients in the number of blue horizontal branch and red giant branch stars. Taken at face value, such gradients would imply an inverse mass segregation, but this interpretation is not fully secure. In any case, their dynamical understanding remains a problem.
2 citations
••
TL;DR: In this article, the authors used N-body simulations to study the effects of primordial mass segregation on the early and long-term evolution of star clusters and showed that in segregated clusters early mass loss due to stellar evolution triggers a stronger expansion than for unsegregated clusters.
Abstract: In this paper we use N-body simulations to study the effects of primordial mass segregation on the early and long-term evolution of star clusters. Our simulations show that in segregated clusters early mass loss due to stellar evolution triggers a stronger expansion than for unsegregated clusters. Tidally limited, strongly segregated clusters may dissolve rapidly as a consequence of this early expansion, while segregated clusters initially underfilling their Roche lobe can survive the early expansion and have a lifetime similar to that of unsegregated clusters. Long-lived initially segregated clusters tend to have looser structure and reach core collapse later in their evolution than initially unsegregated clusters. We have also compared the effects of dynamical evolution on the global stellar mass function (MF) of low-mass main sequence stars. In all cases the MF flattens as the cluster loses stars. The amount of MF flattening induced by a given amount of mass loss in a rapidly dissolving initially segregated cluster is less than for an unsegregated cluster. The evolution of the MF of a long-lived segregated cluster, on the other hand, is very similar to that of an initially unsegregated cluster.
2 citations
••
TL;DR: In this article, the authors used the radial velocity data on 414 galaxies in the Coma region of Kent and Gunn and the relevant results of statistical membership to determine the virial mass of the coma cluster and discuss several issues in its kinematics.
2 citations