Related papers: X-ray Group and cluster mass profiles in MOND: Une…
MOND-- modified Newtonian dynamics-- may be viewed as an algorithm for calculating the distribution of force in an astronomical object from the observed distribution of baryonic matter. The fact that it works for galaxies is quite…
There have been several reports of a detection of an unexplained excess of X-ray emission at $\simeq$ 3.5 keV in astrophysical systems. One interpretation of this excess is the decay of sterile neutrino dark matter. The most influential…
A sample of Coma cluster ultra-diffuse galaxies (UDGs) are modelled in the context of Extended Modified Newtonian Dynamics (EMOND) with the aim to explain the large dark matter-like effect observed in these cluster galaxies. We first build…
A wealth of astronomical data indicate the presence of mass discrepancies in the Universe. The motions observed in a variety of classes of extragalactic systems exceed what can be explained by the mass visible in stars and gas. Either (i)…
Since the 1930s, astronomical observations have accumulated evidence that our understanding of the dynamics of galaxies and groups of galaxies is grossly incomplete: assuming the validity of Newton's law of gravity on astronomical scales,…
We test the reliability of mass determination in clusters of galaxies by X-ray observations. The true mass in cluster models is compared to the mass derived by the X-ray emission and X-ray temperature of a model assuming hydrostatic…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is determined by gravitational processes associated with shock heating, adiabatic compression, and non-gravitational processes such as heating by SNe, stellar…
We study the properties of X-ray galaxy clusters in four cold dark matter models with different baryon fraction $\Omega_{BM}$ ranging from 5 to 20 per cent. By using an original three-dimensional hydrodynamic code based on the piecewise…
The Modified dynamics (MOND) has been propounded as an alternative to Dark matter. It imputes the mass discrepancy in galaxy systems to failure of standard dynamics in the limit of small accelerations. After a brief description of the MOND…
We investigate how different models that have been proposed for solving the dark matter problem can fit the velocity dispersion observed around elliptical galaxies, on either a small scale (~ 20kpc) with stellar tracers, such as planetary…
Modified Newtonian dynamics (MOND), which postulates a breakdown of Newton's laws of gravity/dynamics below some critical acceleration threshold, can explain many otherwise puzzling observational phenomena on galactic scales. MOND competes…
The dark matter (DM) haloes around spiral galaxies appear to conspire with their baryonic content: empirically, significant amounts of DM are inferred only below a universal characteristic acceleration scale. Moreover, the discrepancy…
We present the analysis of baryonic and non-baryonic matter distribution in a sample of ten nearby clusters (0.03<z<0.09) with temperatures between 4.7 and 9.4 keV. These galaxy clusters are studied in detail using X-ray data and global…
We present the baryon fractions of 2MASS groups and clusters as a function of cluster richness using total and gas masses measured from stacked ROSAT X-ray data and stellar masses estimated from the infrared galaxy catalogs. We detect X-ray…
A new, three-dimensional, shock capturing, TVD hydrodynamic code is utilized to determine the distribution of hot gas in a CDM$+\Lambda$ model universe. This open model succeeds in matching local observations of clusters in contrast to the…
The abundance of local clusters is a traditional way to derive the amplitude of matter fluctuations. In the present work, by assuming that the observed baryon content of clusters is representative of the universe, we show that the mass…
Vertical stellar kinematics+density can be used to trace the dark matter distribution [or the equivalent phantom mass in a Modified Newtonian Dynamics (MOND) scenario] through Jeans equations. In this paper, we want to improve this type of…
A detailed analysis of the November 15, 2006 data release (Clowe et al., 2006) X-ray surface density Sigma-map and the strong and weak gravitational lensing convergence kappa-map for the Bullet Cluster 1E0657-558 is performed and the…
Gravitational lensing by clusters of galaxies has been detected on scales ranging from $\sim10^{-1}$ Mpc to $\sim10$ Mpc, namely, arcs/arclets, weak lensing and quasar-cluster associations. This allows us to derive an overall radius matter…
The thermodynamics of the diffuse, X-ray emitting gas in clusters and groups of galaxies are affected by a certain amount of non-gravitational energy input, as indicated by the scaling properties of X-ray halos. Such a view has been…