相关论文: Core Formation by a Population of Massive Remnants

Why do some clusters have cool cores while others do not? In this paper, cosmological simulations, including radiative cooling and heating, are used to examine the formation and evolution of cool core (CC) and non-cool core (NCC) clusters.…

Globular clusters formed in galactic mergers (e.g., The Antennae) can now be studied at different stages of their evolution. In young merger remnants (e.g., NGC 7252) these "second-generation" globulars appear by the hundreds as young halo…

A fundamental issue in star formation is understanding the precise mechanisms leading to the formation of prestellar cores, and their subsequent gravitationally unstable evolution. To address this question, we carefully construct a suite of…

It is suggested that there have been at least two physically distinct epochs of massive cluster formation. The first generation of globular clusters may have formed as halo gas was compressed by shocks driven inward by ionization fronts…

Observations indicate that young massive star clusters in spiral and dwarf galaxies follow a relation between luminosity of the brightest young cluster and the star-formation rate (SFR) of the host galaxy, in the sense that higher SFRs lead…

Massive stars influence their surroundings through radiation, winds, and supernova explosions far out of proportion to their small numbers. However, the physical processes that initiate and govern the birth of massive stars remain poorly…

Protostars and young stars are strongly spatially "clustered" or "correlated" within their natal giant molecular clouds (GMCs). We demonstrate that such clustering leads to the conclusion that the incident bolometric radiative flux upon a…

Observations of pre-/proto-stellar cores in young star-forming regions show them to be mass segregated, i.e. the most massive cores are centrally concentrated, whereas pre-main sequence stars in the same star-forming regions (and older…

We present details of the database from a large Cycle 7 HST project to study the formation and evolution of rich star clusters in the Large Magellanic Cloud (see Elson et al., this volume). Our data set, which includes NICMOS, WFPC2 and…

There are at least 2 distinct mechanisms for the formation of young massive clusters (YMC), all of which require galactic-scale processes. One operates in harrassed fragile galaxies, in the dense cores of low mass galaxies, at the ends of…

In the first part of this article, we review observations of the mass and luminosity functions of young and old star cluster systems. We also review some of the physical processes that may determine the characteristic mass of globular…

We present calculations on the formation of massive black holes with 10^5 Msun at z > 6 that can be the seeds of supermassive black holes at z > 6. Under the assumption of compact star cluster formation in merging galaxies, star clusters in…

A supersonic cloud-cloud collision produces a shock-compressed layer which leads to formation of high-mass stars via gravitational instability. We carried out a detailed analysis of the layer by using the numerical simulations of…

Young, massive star clusters are the most notable and significant end products of violent star-forming episodes triggered by galaxy collisions, mergers, and close encounters. The question remains, however, whether or not at least a fraction…

A large fraction of bulgeless disk galaxies contain young compact stellar systems at their centers, in spite of the local gravitational stability of these disks. We evaluate two contrasting hypotheses for the origin of the nuclear star…

Giant planet embryos are believed to be spawned by gravitational instability in massive extended (R ~ 100 AU) protostellar discs. In a recent paper we have shown that dust can sediment inside the embryos, as argued earlier by Boss (1998) in…

Stars are forming in our galaxy at a rate of between 1 and 4 solar masses of stars per year. In contrast to elliptical galaxies, which are largely devoid of star formation, star formation is still going on in spiral galaxies because of…

The dynamics of galactic nuclei can be affected by several mechanisms. Among these are stellar evolution, stellar collisions, mass segregation, and tidal disruptions of stars due to the central black hole. In this presentation I will…

We study effect of magnetic field on massive dense core formation in colliding unequal molecular clouds by performing magnetohydrodynamic simulations with sub-parsec resolution (0.015 pc) that can resolve the molecular cores. Initial clouds…

A number of globular clusters appear to have undergone core collapse, in the sense that their predicted collapse time is much shorter than their current age. Simulations using gas models and Fokker-Planck approximation have shown that the…