Related papers: Galaxy groups in various evolutionary stages
Numerical simulations as well as optical and X-ray observations over the last few years have shown that poor groups of galaxies can evolve to what is called a fossil group. Dynamical friction as the driving process leads to the coalescence…
We use a set of twelve high-resolution N-body/hydrodynamical simulations in the $\Lambda$CDM cosmology to investigate the origin and formation rate of fossil groups (FGs), which are X-ray bright galaxy groups dominated by a large elliptical…
We present a new sample of 25 fossil groups (FGs) at z < 0.1, along with a control sample of seventeen bright ellipticals located in non-fossil systems. Both the global properties of FGs (e.g. X-ray luminosity) as well as the photometric…
We report the discovery of 12 new fossil groups of galaxies, systems dominated by a single giant elliptical galaxy and cluster-scale gravitational potential, but lacking the population of bright galaxies typically seen in galaxy clusters.…
Fossil groups (FGs) are galaxy aggregates with an extended and luminous X-ray halo, which are dominated by a very massive early-type galaxy and lack of L* objects. FGs are indeed characterized by a large magnitude gap between their central…
We use SDSS-DR4 photometric and spectroscopic data out to redshift z~0.1 combined with ROSAT All Sky Survey X-ray data to produce a sample of twenty-five fossil groups (FGs), defined as bound systems dominated by a single, luminous…
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…
Fossil groups (FGs) have been discovered twenty-five years ago, and are now defined as galaxy groups with an X-ray luminosity higher than $10^{42}\ h_{50}^{-2}$ erg s$^{-1}$ and a brightest group galaxy brighter than the other group members…
Fossil systems are defined to be X-ray bright galaxy groups with a 2-magnitude difference between their two brightest galaxies within half the projected virial radius,and represent an interesting extreme of the population of galaxy…
Galaxy star formation rates (SFRs) are sensitive to the local environment; for example, the high-density regions at the cores of dense clusters are known to suppress star formation. It has been suggested that galaxy transformation occurs…
We analyse the large-scale structure out to 100 Mpc around a sample of 16 confirmed fossil systems using spectroscopic information from the Sloan Digital Sky Survey Data Release 16. We compute the distance between our FGs and the centres of…
(Abridged) Fossil systems are group- or cluster-sized objects whose luminosity is dominated by a very massive central galaxy. In the current cold dark matter scenario, these objects formed hierarchically at an early epoch of the Universe…
We present a pedagogical review on the formation and evolution of galaxies in groups, utilizing observational information from the Local Group to galaxies at z~6. The majority of galaxies in the nearby universe are found in groups, and…
(Abridged) We determine the quantitative morphology and star formation properties of galaxies in six nearby X-ray detected, poor groups using multi-object spectroscopy and wide-field R imaging. We measure structural parameters for each…
The evolution of galaxies in groups may have important implications for the evolution of the star formation history of the universe, since many processes which operate in groups may suppress star formation and the fraction of galaxies in…
We investigate the galaxy populations in seven X-ray selected, intermediate-redshift groups (0.2<z<0.6). Overall, the galaxy populations in these systems are similar to those in clusters at the same redshift; they have large fractions of…
The presence of substructure in galaxy groups and clusters is believed to be a sign of recent galaxy accretion and can be used not only to probe the assembly history of these structures, but also the evolution of their member galaxies.…
We examine galaxy groups from the present epoch to z = 1 to explore the impact of group dynamics on galaxy evolution. We use group catalagues from the Sloan Digital Sky Survey (SDSS), the Group Environment and Evolution Collaboration (GEEC)…
The most accepted scenario for the origin of fossil groups (FGs) is that they are galaxy associations in which the merging rate was fast and efficient. These systems have assembled half of their mass at early epoch of the Universe,…
We use a new fiber spectroscopic survey of 12 nearby, poor groups of galaxies to examine the dynamics and evolution of galaxies in these common, but poorly studied, environments. Some of our conclusions are: (1) The nine groups in our…