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Recently, very massive compact stellar systems have been discovered in the intracluster regions of galaxy clusters and in the nuclear regions of late-type disk galaxies. It is unclear how these compact stellar systems -- known as…
This study compiles stellar populations and internal properties of ultra-diffuse galaxies (UDGs) to highlight correlations with their local environment, globular cluster (GC) richness, and star formation histories. Complementing our sample…
We have used the 2dF spectrograph on the Anglo-Australian Telescope to obtain a complete spectroscopic sample of all objects in the magnitude range, Bj= 16.5 to 19.8, regardless of morphology, in an area centred on the Fornax Cluster of…
Dwarf galaxies have attracted increased attention in recent years, because of their susceptibility to galaxy transformation processes within rich galaxy clusters. Direct evidence for these processes, however, has been difficult to obtain,…
In a large scale view of the universe, galaxies are the basic unit of structure. A typical bright galaxy may contain 100 billion stars and span tens of thousands of light years, but the empty expanses between the galaxies are much larger…
Dwarf galaxies (DGs) serve as extremely challenging objects in extragalactic astrophysics. Their origin is expected to be set as the first units in CDM cosmology. Nevertheless they are the galaxy type most sensitive to environmental in…
A recent all-object spectroscopic survey centred on the Fornax cluster of galaxies, has discovered a population of sub-luminous and extremely compact members, called ``ultra-compact dwarf'' (UCD) galaxies. In order to clarify the origin of…
Despite their apparent fragile appearance, dwarf spheroidals are the most common galaxy type in clusters. In this paper we consider some of the issues associated with two major models for the origin of these dwarfs: primeval galaxies which…
Following the recent surge of interest in peculiar galaxies at high redshifts we consider the definition, or lack thereof, of morphological peculiarities on a sample of local universe galaxies. Studying the morphology of local universe…
Their ubiquity and extreme densities make star clusters probes of prime importance of galaxy evolution. Old globular clusters keep imprints of the physical conditions of their assembly in the early Universe, and younger stellar objects,…
Properties of nearby dwarf galaxies are briefly discussed. Dwarf galaxies vary widely in their star formation histories, the ages of their subpopulations, and in their enrichment history. Furthermore, many dwarf galaxies show evidence for…
Ultra-diffuse galaxies (UDGs) are unusual galaxies with low luminosities, similar to classical dwarf galaxies, but sizes up to $\sim\!5$ larger than expected for their mass. Some UDGs have large populations of globular clusters (GCs),…
In this paper, the first in a series on galaxy formation before reionization, we focus on understanding what determines the size and morphology of stellar objects in the first low mass galaxies, using parsec- scale cosmological simulations…
We numerically investigate dynamical evolution of non-nucleated dwarf elliptical/spiral galaxies (dE) and nucleated ones (dE,Ns) in clusters of galaxies in order to understand the origin of intracluster stellar objects, such as intracluster…
We discuss how knowledge of the whole evolutionary history of dwarf galaxies, including details on the early star formation events, can provide insight on the origin of the different dwarf galaxy types. We suggest that these types may be…
It has been suggested that ultra-compact dwarf (UCD) galaxies are the "threshed'" remains of larger galaxies. Simulations have revealed that extensive tidal-stripping may pare a galaxy back to its tightly-bound, compact nuclear star…
At which masses does the regime of globular clusters end and the one of dwarf galaxies begin? And what separates these two classes of hot stellar systems? We examine to what extend very massive (>10^7 Mo) young star clusters are similar to…
I review recent and less recent work on globular cluster systems in early-type galaxies. Explaining their properties and possible assembly scenarios, touches on a variety of astrophysical topics from cluster formation itself to galaxy…
Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf…
We investigate the connection between globular clusters and ultra-compact dwarf galaxies (UCDs) by examining the properties of several compact objects associated with M87, all of which were previously classified as globular clusters.…