Related papers: Do ultra compact dwarf galaxies form monolithicall…
CONTEXT: The dynamical mass-to-light (M/L) ratios of massive ultra-compact dwarf galaxies (UCDs) are about 50% higher than predicted by stellar population models. AIMS: Here we investigate the possibility that these elevated M/L ratios are…
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.…
Recent spectroscopic observations of galaxies in the Fornax-Cluster reveal nearly unresolved `star-like' objects with red-shifts appropriate to the Fornax-Cluster. These objects have intrinsic sizes of about 100 pc and absolute B-band…
Recent spectroscopic observations of galaxies in the Fornax-Cluster reveal nearly unresolved `star-like' objects with red-shifts appropriate to the Fornax-Cluster. These objects have intrinsic sizes of about 100 pc and absolute B-band…
Photometric surveys of galaxy clusters have revealed a large number of ultra compact dwarfs (UCDs) around predominantly massive elliptical galaxies. Their origin is still debated as some UCDs are considered to be the remnant nuclei of…
The stellar initial mas function (IMF) has been described as being invariant, bottom heavy or top-heavy in extremely dense star burst conditions. To provide usable observable diagnostic we calculate redshift dependent spectral energy…
Some ultra-compact dwarf galaxies have large dynamical mass to light (M/L) ratios and also appear to contain an overabundance of LMXB sources, and some Milky Way globular clusters have a low concentration and appear to have a deficit of…
The name "Ultra-Compact Dwarf Galaxy" (UCD) was invented for a new type of astronomical object that has been discovered in cores of nearby galaxy clusters a decade ago. UCDs resemble globular clusters, but are up to 100 times more massive…
Ultra-compact dwarf galaxies (UCDs) are a new type of galaxy we have discovered in the central region of the Fornax and Virgo clusters. Unresolved in ground-based imaging, UCDs have spectra typical of old stellar systems. Ninety-two have…
Interacting galaxies often have complexes of hundreds of young stellar clusters of individual masses $\sim 10^{4-6}~M_\odot$ in regions that are a few hundred parsecs across. These cluster complexes interact dynamically, and their…
Ultra Compact Dwarf Galaxies (UCDs) and dwarf galaxy nuclei have many common properties, such as internal velocity dispersions and colour-magnitude trends, suggesting tidally stripped dwarf galaxies as a possible UCD origin. However, UCDs…
Ultra-compact dwarf galaxies (UCDs) were serendipitously discovered by spectroscopic surveys in the Fornax cluster twenty years ago. Nowadays, it is commonly accepted that many bright UCDs are the nuclei of galaxies that have been stripped.…
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…
The origin of ultracompact dwarfs (UCDs), a class of compact stellar systems discovered two decades ago, still remains a matter of debate. Recent discoveries of central supermassive black holes in UCDs likely inherited from their massive…
Ultracompact dwarf galaxies (UCDs) are among the densest stellar systems in the universe. These systems have masses up to 200 million solar masses, but half light radii of just 3-50 parsecs. Dynamical mass estimates show that many UCDs are…
We present new imaging and spectroscopic observations of six ultra-compact dwarf (UCD) galaxies in the Virgo Cluster, along with re-analysed data for five Fornax Cluster UCDs. These are the most luminous UCDs: -14<Mv<-12 mag. Our HST…
We propose that there is an evolutionary link between ultra-compact blue dwarf galaxies (UCBDs) with active star formation and nucleated dwarfs based on the results of numerical simulations of dwarf-dwarf merging. We consider the…
We present preliminary results of the search for Ultra-compact dwarf galaxies in the central region of the Antlia cluster. This new kind of stellar system has brightness, mass and size between those observed in globular clusters and…
We have discovered a new type of galaxy in the Fornax Cluster: ``ultra-compact'' dwarfs (UCDs). The UCDs are unresolved in ground-based imaging and have spectra typical of old stellar systems. Although the UCDs resemble overgrown globular…
Recent observational studies of ultra-compact dwarf galaxies (UCDs) have discovered massive black holes (MBHs) with masses of more than ${10^6~\rm M_\odot}$, in their central regions. We here consider that these MBHs can be formed through…