Related papers: Galaxy Groups within 3500 km s$^{-1}$
The relationship between galaxies and dark matter can be characterized by the halo mass of the central galaxy and the fraction of galaxies that are satellites. Here we present observational constraints from the SDSS on these quantities as a…
Using observations in the COSMOS field, we report an intriguing correlation between the star formation activity of massive (~10^{11.4}\msol) central galaxies, their stellar masses, and the large-scale (~10 Mpc) environments of their…
All galaxies are thought to reside within large halos of dark matter, whose properties can only be determined from indirect observations. The formation and assembly of galaxies is determined from the interplay between these dark matter…
The stellar content of galaxies is tightly connected to the mass and growth of their host dark matter halos. Observational constraints on this relation remain limited, particularly for low-mass groups, leaving uncertainties in how galaxies…
The Survey of HI in Extremely Low-mass Dwarfs (SHIELD) includes a volumetrically complete sample of 82 gas-rich dwarfs with M_HI~<10^7.2 Msun selected from the ALFALFA survey. We are obtaining extensive follow-up observations of the SHIELD…
Five galaxy groups with properties similar to those of the Local Group have been surveyed for HI clouds with the Arecibo Telescope. In total 300 pointings have been observed on grids of approximately 2.5 x 1.5 Mpc centred on the groups. The…
Reliable halo mass estimation for a given galaxy system plays an important role both in cosmology and galaxy formation studies. Here we set out to find the way that can improve the halo mass estimation for those galaxy systems with limited…
Elucidating the connection between the properties of galaxies and the properties of their hosting haloes is a key element in galaxy formation. When the spatial distribution of objects is also taken under consideration, it becomes very…
For almost twenty years models of the Galaxy have included a dark halo responsible for supporting a substantial fraction of the local rotation velocity and a flat rotation curve at large distances. Estimates of the local halo density range…
We use a high resolution $\Lambda$CDM numerical simulation to calculate the mass function of dark matter haloes down to the scale of dwarf galaxies, back to a redshift of fifteen, in a 50 $h^{-1}$Mpc volume containing 80 million particles.…
The formation of galactic discs and the efficiency of star formation within them are issues central to our understanding of galaxy formation. We have developed a detailed and versatile model of disc formation which combines the strengths of…
The question we address in this paper is the determination of the correlation properties of the dark matter halos appearing in cosmic density fields once they underwent a strongly nonlinear evolution induced by gravitational dynamics.…
We propose a heuristic model that displays the main features of realistic theories for galaxy bias. We show that the low-order clustering statistics of the dark-matter distribution depend almost entirely on the locations and density…
We study the environment in which a galaxy lies (i.e. field or group) and its connection with the morphology of the galaxy. This is done by examining the distribution of parametric and non-parametric statistics across the star-formation…
We use dark matter haloes identified in the MareNostrum Universe and galaxy groups identified in the Sloan Data Release 7 galaxy catalogue, to study the relation between halo shape and halo dynamics, parametrizing out the mass of the…
The atomic hydrogen (HI) properties of star-forming galaxies in the local Universe are known to correlate with other galaxy properties via the ``HI scaling relations''. The redshift evolution of these relations serves as an important…
We present a new, galaxy-halo model of large-scale structure, in which the galaxies entering a given sample are the fundamental objects. Haloes attach to galaxies, in contrast to the standard halo model, in which galaxies attach to haloes.…
Galaxy groups and poor clusters are more common than rich clusters, and host the largest fraction of matter content in the Universe. Hence, their studies are key to understand the gravitational and thermal evolution of the bulk of the…
The formation process, properties, and spatial distribution of galaxy groups and clusters are closely related to the background cosmological model. We use numerical simulations of variants of the CDM model with different cosmological…
A new view on our Galaxy has recently emerged, with large consequences on its formation scenarios. Not only new dwarf satellites have been detected, still orbiting and tidally disrupting, but also a multitude of stellar streams or tidal…