Related papers: Galaxy Groups: Proceedings from a Swinburne Univer…
We are carrying out a comprehensive multi-wavelength study of dwarf galaxies in the Local Volume (< 5 Mpc). After our all-sky survey more than doubled the dwarf census we are now measuring structural parameters, integrated properties, and…
Optical and X-ray studies have established the prevalence of significant substructure in clusters of galaxies, indicating that clusters are young systems, and that recent major mergers have occurred in many clusters. Numerical simulations…
In this Research Highlights, we summarize 31 contributions provided during the Workshop \textit{Multifrequency Behaviour of High Energy Cosmic Sources - XIV}, held in Palermo (Italy) from the 12th to the 17th of June 2023. We will start…
In a recent multiwavelength study of galaxies at redshift ~ 2 by Daddi et al. (2007a,b) it is shown that galaxies with a Mid-IR excess most likely harbor a Compton-thick AGN, thus bringing to about 1/3 the fraction of z ~ 2 galaxies hosting…
We have redefined group membership of six southern galaxy groups in the local universe (mean cz < 2000 km/s) based on new redshift measurements from our recently acquired Anglo-Australian Telescope 2dF spectra. For each group, we…
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…
Nearby galaxy groups of comparable mass to the Local Group show global variations that reflect differences in their evolutionary history. Satellite galaxies in groups have higher levels of gas deficiency as the distance to their host…
Interactions between galaxies have spectacular effects on gas dynamics, and small galaxy groups are a privileged place to investigate them. In particular, they could test the existence of cold H2 gas as dark matter in the outer parts of…
We report a list of groups consisting of dwarf galaxies only. The sample contains 126 objects, mainly combined in pairs. The most populated group contains six dwarf galaxies. The majority of systems considered reside in the low-density…
Fossil groups are expected to be the final product of galaxy merging within galaxy groups. In simulations, they are predicted to assemble their mass at high redshift. This early formation allows for the innermost $M^\ast$ galaxies to merge…
These lectures are intended to provide an introduction to the rich interplay between N-body simulations and stellar-kinematic observations of galaxies. The first section describes the kinematic properties of galaxies that are accessible to…
Galaxy groups contain the majority of bound mass with a significant portion of baryons due to the combination of halo mass and abundance (Cui 2024). Hence they serve as a crucial missing piece in the puzzle of galaxy formation and the…
I present written notes from three lectures given at the 54th Saas-Fee Advanced Course of the Swiss Society of Astrophysics and Astronomy in January 2025 entitled "Galaxies and Black Holes in the First Billion Years as seen by the JWST". I…
The galaxies of the Local Group that are currently forming stars can serve as our laboratories for understanding star formation and the evolution of massive stars. In this talk I will summarize what I think we've learned about these topics…
Multi-wavelength observations of Hickson's Compact Groups (HCGs) have shown that many of these groups are physical bound structures and are in different stage of evolution, from spiral-dominated systems to almost merged objects. Very few…
This contribution to the published Proceedings records the opening talk I presented on the first morning of the 2005 International Linear Collider Workshop in Snowmass, CO, August 14 - 27, 2005. It includes a summary of the motivation for…
This expository article builds on lecture notes from a minicourse entitled "Cremona groups and CAT(0) cube complexes" and given by the author as part of the 2023 Riverside Workshop on Geometric Group Theory. It presents recent constructions…
The workshop "New directions in modern cosmology", organized by Theo Nieuwenhuizen, Rudy Schild, Francesco Sylos Labini and Ruth Durrer, was held from September 27 until October 1, 2010, in the Lorentz Center in Leiden, the Netherlands. A…
Compact groups of galaxies provide a unique environment to study the evolution of galaxies amid frequent gravitational encounters. These nearby groups have conditions similar to those in the earlier universe when galaxies were assembled and…
We perform statistical analyses to study the infall of galaxies onto groups and clusters in the nearby Universe. The study is based on the UZC and SSRS2 group catalogs and peculiar velocity samples. We find a clear signature of infall of…