Related papers: Fossil Groups Origins III. The relation between op…
We present the first pointed X-ray observations of 10 candidate fossil galaxy groups and clusters. With these Suzaku observations, we determine global temperatures and bolometric X-ray luminosities of the intracluster medium (ICM) out to…
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 present a combined optical and X-ray analysis of three optically selected X-ray bright groups with giant elliptical galaxies in the center. These massive ellipticals were targeted for XMM-Newton X-ray observations based on their large…
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…
Fossil groups are systems with one single central elliptical galaxy and an unusual lack of luminous galaxies in the inner regions. The standard explanation for the formation of these systems suggests that the lack of bright galaxies is due…
(Abridged) Fossil systems are galaxy associations dominated by a relatively isolated, bright elliptical galaxy, surrounded by a group of smaller galaxies lacking L* objects. We analyzed the near-infrared photometric and structural…
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…
We present the global group properties of two samples of galaxy groups containing 39 high quality X-ray selected systems and 38 optically (spectroscopically) selected systems in coincident spatial regions at 0.12<z<0.79. Only nine optical…
We present a comparison of X-ray and optical luminosities and luminosity functions of cluster candidates from a joint optical/X-ray survey, the ROSAT Optical X-Ray Survey. Completely independent X-ray and optical catalogs of 23 ROSAT fields…
In this work we study the large-scale structure around a sample of non-fossil systems and compare the results with earlier findings for a sample of genuine fossil systems selected using their magnitude gap. We compute the distance from each…
We study the ratio of luminous-to-faint red sequence galaxies in both optically and X-ray selected galaxy clusters in the poorly studied redshift range 0.05< z<0.19. The X-ray selected sample consists of 112 clusters based on the ROSAT…
This paper presents both the result of a search for fossil systems (FSs) within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results of a study of the stellar mass assembly and stellar populations of their fossil…
It has been a long-standing question whether fossil groups are just sampling the tail of the distribution of ordinary groups, or whether they are a physically distinct class of objects, characterized by an unusual and special formation…
We compare the X-ray properties of loose and compact galaxy groups, using a combined sample of 42 groups. We find that we are unable to separate loose and compact groups on the luminosity-temperature relation, the luminosity-velocity…
We have derived the X-ray luminosities of a sample of galaxies in groups, making careful allowance for contaminating intragroup emission. The L_X:L_B and L_X:L_{FIR} relations of spiral galaxies in groups appear to be indistinguishable from…
We present a catalogue of X-ray luminosities for 401 early-type galaxies, of which 136 are based on newly analysed ROSAT PSPC pointed observations. The remaining luminosities are taken from the literature and converted to a common energy…
Properties of the hot intracluster and intragroup medium are mostly set by the underlying gravitational potential well, although complex astrophysical processes at play during their buildup may leave a significant imprint. Observational…
We investigate the origin and evolution of fossil groups in a concordance LCDM cosmological simulation. We consider haloes with masses between $(1-5)\times10^{13} \hMsun$ and study the physical mechanisms that lead to the formation of the…
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 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…