Related papers: A Simple and Accurate Model for Intra-Cluster Gas
Hydrodynamical simulations indicate that substantial fraction of baryons in the Universe remains in a diffuse component - Warm-Hot Intergalactic Medium (WHIM). To determine physical properties (spatial distribution, temperature and density)…
Efforts to understand the deviation of the L--T relation from a simple scaling law valid for clusters and groups have triggered a number of interesting studies on the subject. Techniques and approaches differ widely but most works agree on…
We study the thermodynamic properties of the hot gas in a sample of groups in the 0.012-0.024 redshift range, using XMM-Newton observations. We present measurements of temperature, entropy, pressure and iron abundance. Non-parametric fits…
The dynamical mass of clusters of galaxies, calculated in terms of modified Newtonian dynamics, is a factor of two or three times smaller than the Newtonian dynamical mass but remains significantly larger than the observed baryonic mass in…
(Abridged) We revisit the scaling relationships between the dark matter mass and observed X-ray luminosity and temperature of galaxy clusters and groups in the local Universe. Specifically, we compare recent observations with analytic…
High-resolution cosmological N-body simulations are excellent tools for modelling the formation and clustering of dark matter haloes. These simulations suggest complex physical theories of halo formation governed by a set of effective…
We study and model the properties of galaxy clusters in the normal-branch Dvali-Gabadadze-Porrati (nDGP) model of gravity, which is representative of a wide class of theories which exhibit the Vainshtein screening mechanism. Using the first…
The logotropic model [P.H. Chavanis, Eur. Phys. J. Plus {\bf 130}, 130 (2015)] may be an interesting alternative to the $\Lambda$CDM model. It is able to account for the present accelerating expansion of the universe while solving at the…
We analyse the radial structure of self-gravitating spheres consisting of multiple interpenetrating fluids, such as the X-ray emitting gas and the dark halo of a galaxy cluster. In these dipolytropic models, adiabatic dark matter sits in…
Virialized systems, such as clusters and groups of galaxies, represent an ideal laboratory for investigating the formation and evolution of structure on the largest scales. Furthermore, the properties of the gaseous intracluster medium…
In this review, we describe our current understanding of cluster formation: from the general picture of collapse from initial density fluctuations in an expanding Universe to detailed simulations of cluster formation including the effects…
We revive the historically first dark matter model based on neutrinos, but with an additional assumption that neutrinos might exist in tachyonic almost sterile states. To this end, we propose a group-theoretical algorithm for the…
Using the largest mosaic of Hubble Space Telescope images around a galaxy cluster, we map the distribution of dark matter throughout a $\sim$$6\times6$ Mpc$^2$ area centred on the cluster MS 0451-03 ($z=0.54$, $M_{200}=1.65\times10^{15}…
We investigate the formation of spherical cosmological structures following both dark matter and gas components. We focus on the dynamical aspect of the collapse assuming an adiabatic, $\gamma = 5/3$, fully ionized primordial plasma. We use…
The aim of the present work is to show that, contrary to popular belief, galaxy clusters are **not** expected to be self-similar, even when the only energy sources available are gravity and shock-wave heating. In particular, we investigate…
We present results of X-ray observations of a sample of 15 clusters selected via their imprint on the cosmic microwave background (CMB) from the thermal Sunyaev-Zel'dovich (SZ) effect. These clusters are a subset of the first SZ-selected…
We present a spherically symmetric model for the origin and evolution of the temperature profiles in the hot plasma filling galaxy groups and clusters. We find that the gas in clusters is generically not isothermal, and that the temperature…
The outskirts of galaxy clusters present a promising avenue for constraining cluster masses in a way that is robust to the impact of baryonic physics. We assess the accuracy to which the cluster infall regions can be used to for cluster…
Context. Galaxy cluster masses are usually defined as the mass within a spherical region enclosing a given matter overdensity (in units of the critical density). Converting masses from one overdensity definition to another can have several…
Galaxy clusters can be used as powerful cosmological probes, provided one can obtain accurate mass estimates, which requires a precise knowledge of the underlying astrophysics of galaxy clusters. For these purposes, spatially resolved…