scispace - formally typeset
Search or ask a question
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
More filters
Journal ArticleDOI
TL;DR: In this article, the authors make use of the homogeneity, depth and sky coverage of the 2MASS catalogue to study spatial variations of the stellar luminosity function in the intermediate age cluster M 67 (NGC 2682).
Abstract: We make use of the homogeneity, depth and sky coverage of the 2MASS catalogue to study spatial variations of the stellar luminosity function in the intermediate age cluster M 67 (NGC 2682). We find that the central region ( R< 3:3 0 )h as a depletion of G 0 and G 5 stars with respect to the intermediate annulus (3:3 0 < R< 7:4 0 ) and the halo (12 0 < R< 24 0 ). In the non-eroded part of the mass function the slope is steeper in the intermediate annulus than in the central region, suggesting an enhancement of F 0 stars with respect to turno and A 5 stars in the latter zone. In the halo, the G 0-G 5 stars are not depleted as compared to the central region, but the overall mass function slope is rather shallow. This suggests that the halo is enriched in low mass stars, transferred there from the inner parts as a consequence of the internal dynamical evolution, but tidal losses to the Galactic field have also been important.

73 citations

Journal ArticleDOI
TL;DR: In this article, the authors show that mass segregation is not observable in clusters with a high black hole retention fraction (>50 per cent after supernova kicks and >50 per percent after dynamical evolution).
Abstract: Dalessandro et al. observed a similar distribution for blue straggler stars and main-sequence turn-off stars in the Galactic globular cluster NGC 6101, and interpreted this feature as an indication that this cluster is not mass-segregated. Using direct N-body simulations, we find that a significant amount of mass segregation is expected for a cluster with the mass, radius and age of NGC 6101. Therefore, the absence of mass segregation cannot be explained by the argument that the cluster is not yet dynamically evolved. By varying the retention fraction of stellar-mass black holes, we show that segregation is not observable in clusters with a high black hole retention fraction (>50 per cent after supernova kicks and >50 per cent after dynamical evolution). Yet all model clusters have the same amount of mass segregation in terms of the decline of the mean mass of stars and remnants with distance to the centre. We also discuss how kinematics can be used to further constrain the presence of a stellar-mass black hole population and distinguish it from the effect of an intermediate-mass black hole. Our results imply that the kick velocities of black holes are lower than those of neutron stars. The large retention fraction during its dynamical evolution can be explained if NGC 6101 formed with a large initial radius in a Milky Way satellite.

73 citations

Journal ArticleDOI
TL;DR: In this article, a revised X-ray source list of the Trumpler 16 region contains 1232 sources, including 1187 likely Carina members, which is matched to 1047 near-infrared counterparts detected by the HAWK-I instrument at the Very Large Telescope.
Abstract: Trumpler 16 is a well-known rich star cluster containing the eruptive supergiant ? Carinae and located in the Carina star-forming complex. In the context of the Chandra Carina Complex Project, we study Trumpler 16 using new and archival X-ray data. A revised X-ray source list of the Trumpler 16 region contains 1232 X-ray sources including 1187 likely Carina members. These are matched to 1047 near-infrared counterparts detected by the HAWK-I instrument at the Very Large Telescope allowing for better selection of cluster members. The cluster is irregular in shape. Although it is roughly circular, there is a high degree of sub-clustering, with no noticeable central concentration and an extension to the southeast. The high-mass stars show neither evidence of mass segregation nor evidence of strong differential extinction. The derived power-law slope of the X-ray luminosity function for Trumpler 16 reveals a much steeper function than the Orion Nebula Cluster, implying a different ratio of solar- to higher-mass stars. We estimate the total Trumpler 16 pre-main-sequence population to be >6500 Class II and Class III X-ray sources. An overall K-excess disk frequency of ~8.9% is derived using the X-ray-selected sample, although there is some variation among the sub-clusters, especially in the southeastern extension. X-ray emission is detected from 29 high-mass stars with spectral types between B2 and O3.

73 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present the results of a comprehensive analysis of the structure and kinematics of six Galactic globular clusters and determine the stellar and dynamical masses of these stellar systems taking into account the effect of mass segregation, anisotropy, and unresolved binaries.
Abstract: We present the results of a comprehensive analysis of the structure and kinematics of six Galactic globular clusters. By comparing the results of the most extensive photometric and kinematical surveys available to date with suitable dynamical models, we determine the stellar and dynamical masses of these stellar systems taking into account the effect of mass segregation, anisotropy, and unresolved binaries. We show that the stellar masses of these clusters are on average smaller than those predicted by canonical integrated stellar evolution models because of the shallower slopes of their mass functions. The derived stellar masses are found to be also systematically smaller than the dynamical masses by ~40%, although the presence of systematics affecting our estimates cannot be excluded. If confirmed, this evidence can be linked to an increased fraction of retained dark remnants or to the presence of a modest amount of dark matter.

73 citations

Journal ArticleDOI
TL;DR: In this paper, the initial mass function and mass segregation in super star cluster M82-F with high-resolution Keck NIRSPEC echelle spectroscopy were investigated.
Abstract: We investigate the initial mass function and mass segregation in super star cluster M82-F with high-resolution Keck NIRSPEC echelle spectroscopy. Cross-correlation with template supergiant spectra provides the velocity dispersion of the cluster, enabling measurement of the kinematic (virial) mass of the cluster when combined with sizes from NICMOS and Advanced Camera for Surveys (ACS) images. We find a mass of 6.6 ± 0.9 × 105 M☉ based on near-IR light and 7.0 ± 1.2 × 105 M☉ based on optical light. Using PSF-fitting photometry, we derive the cluster's light-to-mass (L/M) ratio in both near-IR and optical light and compare to population-synthesis models. The ratios are inconsistent with a normal stellar initial mass function for the adopted age of 40-60 Myr, suggesting a deficiency of low-mass stars within the volume sampled. King model light profile fits to new Hubble Space Telescope ACS images of M82-F, in combination with fits to archival near-IR images, indicate mass segregation in the cluster. As a result, the virial mass represents a lower limit on the mass of the cluster.

73 citations


Network Information
Related Topics (5)
Star formation
37.4K papers, 1.8M citations
94% related
Galaxy
109.9K papers, 4.7M citations
94% related
Active galactic nucleus
20.7K papers, 996.7K citations
94% related
Elliptical galaxy
20.9K papers, 1M citations
94% related
Metallicity
19.4K papers, 966.7K citations
93% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202336
202225
202133
202047
201943
201822