Related papers: omega-Cen - an Ultra Compact Dwarf Galaxy ?
We present multi-band photometry covering $\sim$ 5\deg $\times$ 5\deg across $\omega$ Cen collected with the Dark Energy Camera, combined to Hubble Space Telescope and Wide Field Imager data for the central regions. The unprecedented…
The nature and formation history of our Galaxy's largest and most enigmatic stellar cluster, known as Omega Centauri (ocen) remains debated. Here, we offer a novel approach to disentangling the complex stellar populations within ocen based…
(Abridged) We examine the theoretical relationship between Omega_0 and substructure in galaxy clusters which are formed by the collapse of high density peaks in a gaussian random field. The radial mass distributions of the clusters are…
Two competing theories posit that Ultra Compact Dwarfs (UCDs) form either as the stripped nuclei of dwarf galaxies or as giant globular clusters (GGCs) associated with the largest globular cluster (GC) systems. By focussing on the field and…
We compile a sample of spectroscopically- and photometrically-selected cluster galaxies from four high-redshift galaxy clusters ($1.59 < z < 1.71$) from the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS), and a comparison…
Galaxy groups and clusters are the main tools used to test cosmological models and to study the environmental effect of galaxy formation. This work provides a catalogue of galaxy groups and clusters, as well as potentially merging systems…
CCD vby Stroemgren photometry of a statistically complete sample of red giants and stars in the main sequence turn-off region in omega Centauri has been used to analyse the apparently complex star formation history of this cluster. From the…
In this contribution the discovery and properties of ultra-compact dwarf galaxies are presented, and their possible origin is discussed. This new type of galaxy resides in the cores of galaxy clusters. In the fundamental plane diagram of…
Ultra-compact dwarf galaxies (UCDs) are predominatly found in the cores of nearby galaxy clusters. Besides the Fornax and Virgo cluster, UCDs have also been confirmed in the twice as distant Hydra I and Centaurus clusters. Having (nearly)…
Galaxy mergers are crucial for understanding galaxy evolution, and with large upcoming datasets, automated methods such as Convolutional Neural Networks (CNNs) are essential for efficient detection. It is understood that CNNs classify…
Subarcsecond infrared and radio observations yield important information about the formation of super star clusters from their surrounding gas. We discuss the general properties of ionized and molecular gas near young, forming SSCs, as…
We use numerical simulations to investigate the orbital characteristics of tidal debris from satellites whose orbits are dragged into the plane of galactic disks by dynamical friction before disruption. We find that these satellites may…
In this contribution, results from CCD vby Stroemgren photometry of a statistically complete sample of red giants and stars in the main sequence turn-off region in omega Centauri are presented. From the location of stars in the (b-y),m_1…
Galaxies and galaxy clusters trace the same cosmic density field, but their statistics have been modeled separately in cosmological analyses. We present a unified, simulation-based framework to model them using the galaxy-halo connection.…
We discuss the merger rate, close galaxy environment, and clustering on scales up to a Mpc of the SWIFT BAT hard X-ray sample of nearby (z<0.05), moderate-luminosity active galactic nuclei (AGN). We find a higher incidence of galaxies with…
We present a series of $N$-body simulations representing the evolution of a galactic nucleus and its stellar content in a nearly one-to-one representation. The aim of this suite of simulations is to shed light on the interplay between…
In the last decade, extended stellar clusters with masses in the range from a few 10^4 to 10^8 M_sun have been found in various types of galaxies in different environments. Objects with masses comparable to normal globular clusters (GCs)…
We describe a population of compact objects in the centre of the Fornax Cluster which were discovered as part of our 2dF Fornax Spectroscopic Survey. These objects have spectra typical of old stellar systems, but are unresolved on…
We investigate the formation processes of the Galactic globular cluster (GC) omega Cen with multiple stellar populations based on our original hydrodynamical simulations with chemical enrichment by Type II supernovae (SNe II), asymptotic…
We present a multiwavelength analysis of 29 merging galaxy clusters that exhibit radio relics. For each merging system, we perform a weak-lensing analysis on Subaru optical imaging. We generate high-resolution mass maps of the dark matter…