Related papers: Infant Galaxy Clusters at Low Redshifts?
Sensitive optical surveys have revealed a large population of `faint blue galaxies' which are believed to be young galaxies, observed close to their time of formation. But there has been considerable uncertainty regarding the epochs at…
Using Spitzer 3.6 micron data we derived the luminosity function and the mass function of galaxies in five z>1.4 clusters selected to have a firm intracluster medium detection. The five clusters differ in richness (ISCSJ1438.1+3414 and…
We discuss some of the key open questions regarding the formation and evolution of globular clusters (GCs) during galaxy formation and assembly within a cosmological framework. The current state-of-the-art for both observations and…
New ground-based and HST observations of distant clusters make it possible to trace the history of E/S0 galaxies to lookback times of ~10 $h_{50}^{-1}$ Gyr. The data strongly favor a scenario in which cluster ellipticals formed very early…
Recent observations show a large concentration of galaxies at high redshift. At first sight strong clustering of galaxies at high redshifts seems to be in contradiction with the models of structure formation. In this paper we show that such…
A synopsis of the recent results from our study of galaxy-galaxy lensing in clusters is presented. We have applied our analysis techniques to the sample of HST cluster-lenses that span a redshift range from redshift 0.18 to 0.58. We find…
Numerical simulations of a Milky Way-size galaxy demonstrate that globular clusters with the properties similar to observed can form naturally at z > 3 in the concordance Lambda-CDM cosmology. The clusters in our model form in the strongly…
This paper addresses the questions of what we have learned about how and when dense star clusters form, and what studies of star clusters have revealed about galaxy formation and evolution. One important observation is that globular…
Galaxies at very high redshift (z~3 or greater) are now accessible to wholesale observation, making possible for the first time a robust statistical assessment of their spatial distribution at lookback times approaching ~90% of the age of…
Massive clusters of galaxies have been found as early as 3.9 Billion years (z=1.62) after the Big Bang containing stars that formed at even earlier epochs. Cosmological simulations using the current cold dark matter paradigm predict these…
Populations of young star clusters show significant differences even among "normal" disk galaxies. In this contribution I discuss how properties of young cluster systems are related to those of their host galaxies, based on a recent study…
We have measured the 3.6 micron luminosity evolution of about 1000 galaxies in 32 clusters at 0.2<z<1.25, without any a priori assumption about luminosity evolution, i.e. in a logically rigorous way. We find that the luminosity of our…
Star clusters stand at the intersection of much of modern astrophysics: the interstellar medium, gravitational dynamics, stellar evolution, and cosmology. Here we review observations and theoretical models for the formation, evolution, and…
Clusters are the dense inner regions of a wide-spread hierarchy of young stellar structures. They often reveal a continuation of this hierarchy inside of them, to smaller scales, when they are young, but orbital mixing eventually erases…
We study the formation and the evolution of galaxy groups in a critical universe, showing the importance of secondary infall for their dynamical evolution. Merging is only slightly accelerated if galaxies have massive halos, because the…
Mergers of gas-rich galaxies lead to gravitationally driven increases in gas pressure that can trigger intense bursts of star and cluster formation. Although star formation itself is clustered, most newborn stellar aggregates are unbound…
Rapid progress is now being made in the study of stellar populations of galaxies at large lookback times, both in dense clusters and the field. Dramatic transformations in star formation histories (even morphologies) appear to prevail among…
Rich clusters of galaxies are the most massive virialized systems known. Even though they contain only a small fraction of all galaxies, rich clusters provide a powerful tool for the study of galaxy formation, dark matter, large-scale…
Most stars do not form in isolation but as part of a cluster comprising anywhere between a few dozen to several million stars with stellar densities ranging from 0.01 to several 10$^5$ \Msun pc$^{-3}$. The majority of these clusters…
Observations have revealed that most stars are born in clusters. These systems, containing from tens to thousands of stars and typically significant mass in gas in the youngest systems, evolve due to a combination of stellar and star-gas…