相关论文: A search for ultra-compact dwarf galaxies in the C…

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…

We present spectroscopic observations of ultra compact dwarf (UCD) galaxies in the Fornax and Virgo Clusters made to measure and compare their stellar populations. The spectra were obtained on the Gemini-North (Virgo) and Gemini-South…

We present radial velocities (from Gemini/GMOS) of the second sample of ultra-compact dwarfs (UCDs) and bright globular clusters (GCs) in the Antlia cluster. Twenty-three objects are located around the giant elliptical NGC 3268, and one is…

We aim at quantifying the specific frequency of UCDs in a range of environments and at relating this to the frequency of globular clusters (GCs) and potential progenitor dwarf galaxies. Are the frequencies of UCDs consistent with being the…

Various formation channels for the puzzling ultra-compact dwarf galaxies (UCDs) have been proposed in the last few years. To better judge on some of the competing scenarios, we present spectroscopic [Fe/H] estimates for a sample of 26…

We present a study of ultra-diffuse galaxies (UDGs) in the Virgo Cluster based on deep imaging from the Next Generation Virgo Cluster Survey (NGVS). Applying a new definition for the UDG class based on galaxy scaling relations, we define…

Most ultra-compact dwarf galaxies (UCDs) and very massive globular clusters reside in nearby galaxy clusters or around nearby giant galaxies. Due to their distance (>Mpc) and compactness (r_eff<100pc) they are barely resolved, and thus it…

Our VLT (FLAMES) observations near NGC1399 investigate the connection between ultra-compact dwarf galaxies (UCDs), NGC1399 globular clusters and intra-cluster globulars. We have uncovered 30 faint compact stellar systems in the Fornax…

We have discovered both a red and a blue subpopulation of Ultra-Compact Dwarf (UCD) galaxy candidates in the Coma galaxy cluster. We analyzed deep F475W (Sloan g) and F814W (I) Hubble Space Telescope images obtained with the Advanced Camera…

We present the results of a wide spectroscopic survey aimed at detecting extragalactic globular clusters (GCs) in the core of the Fornax cluster. About 4500 low resolution spectra (from 4800 to 10000 \AA ) were observed in 25 VLT/VIMOS…

We present measurements of the galaxy luminosity and stellar mass function in a 3.71 deg$^2$ (0.3 Mpc$^2$) area in the core of the Virgo cluster, based on $ugriz$ data from the Next Generation Virgo Cluster Survey (NGVS). The galaxy sample…

As part of the HST/ACS Coma Cluster Treasury Survey, we have undertaken a Keck/LRIS spectroscopic campaign to determine membership for faint dwarf galaxies. In the process, we discovered a population of Ultra Compact Dwarf galaxies (UCDs)…

The origin of ultracompact dwarf (UCD) galaxies, compact extragalactic stellar systems, is still a puzzle for present galaxy formation models. We present the comprehensive analysis of high resolution multi-object spectroscopic data for a…

We present a photometric search for UCD candidates in the nearby galaxy group NGC 1023 (d=11 Mpc) -- the poorest environment searched for UCDs yet --, based on wide field imaging with CFHT. After photometric and morphological selection, we…

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…

The Fornax Cluster Spectroscopic Survey (FCSS) project utilises the 2dF multi-object spectrograph on the AAT. Its aim is to obtain spectra for a complete sample of all 14000 objects with 16.5<bj<19.7 irrespective of their morphology in a 12…

The origin of ultra-compact dwarfs (UCDs)--objects larger and more massive than typical globular clusters (GCs), but more compact than typical dwarf galaxies--has been hotly debated in the 15 years since their discovery. Even whether UCDs…

A dataset of 23,351 globular clusters (GCs) and ultra-compact dwarfs (UCDs) in the Coma cluster of galaxies was built using Hubble Space Telescope Advanced Camera for Surveys data. Based on the standard magnitude cut of $M_V \leq -11$, a…

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…

Aims. We determine masses and mass-to-light ratios of five ultra-compact dwarf galaxies and one dwarf elliptical nucleus in the Fornax cluster from high resolution spectroscopy. Methods. Velocity dispersions were derived from selected…