Related papers: Lost and found dark matter in elliptical galaxies
Recycled dwarf galaxies can form in the collisional debris of massive galaxies. Theoretical models predict that, contrary to classical galaxies, they should be free of non-baryonic Dark Matter. Analyzing the observed gas kinematics of such…
We investigate the hypothesis that the cores of elliptical galaxies and bulges are created from the binding energy liberated by the coalescence of supermassive binary black holes during galaxy mergers. Assuming that the central density…
I review the results of recent analysis and interpretation of X-ray observations of elliptical galaxies, focusing on elemental abundances and dark matter. The hot ISM is characterized by subsolar Fe abundances and solar Si-to-Fe ratios;…
The formation of galaxies in a CDM cosmogony is investigated by following the evolution of dark and baryonic matter and of the frequency- dependent spatially averaged radiation field. The gas is allowed to form stars which are independently…
We study a possible formation mechanism for elliptical/S0 galaxies using N-body simulations with GRAPE. A close galaxy encounter which does not lead to a merger can induce a strong bar in an initially axisymmetric disk. This bar is unstable…
Elliptical galaxies probably host the most metal rich stellar populations in the Universe. The processes leading to both the formation and the evolution of such stars are discussed by means of a new gas dynamical model which implements…
The mass and anisotropy of an elliptical galaxy can be simultaneously determined from velocity dispersion and line profile shape measurements. We describe the principles, techniques, and limitations of this approach, and the results…
There are many proposed mechanisms driving the morphological transformation of disk galaxies to elliptical galaxies. In this paper, we determine if the observed transformation in low mass groups can be explained by the merger histories of…
We present a numerical study of the properties of the stellar velocity distribution in stellar discs which have developed a saturated, two-armed spiral structure. We follow the growth of the spiral structure deeply into the non-linear…
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…
We show that hard encounters in the central regions of globular clusters embedded in dark matter (DM) haloes necessarily lead to the formation of gravitationally-bound stellar envelopes that extend far beyond the nominal tidal radius of the…
Elliptical galaxies formed in a major merger tend to become more nearly spherical with time, thanks to the gravitational effect of their central black hole (or black holes). Observational results indicate that elliptical galaxies with older…
Using high-accuracy rotation curves of spiral galaxies, we derive distributions of the surface mass density. Comparing with the luminosity profiles, we show that the dark mass in disk and bulge distributions follows those of luminous…
The most massive elliptical galaxies have low-density centers or cores that differ dramatically from the high-density centers of less massive ellipticals and bulges of disk galaxies. These cores have been interpreted as the result of…
The temperature of hot interstellar gas at large radii in elliptical galaxies can be lower than the mean galactic virial temperature. If so, a nonlinear cooling wave can form in the hot interstellar gas and propagate slowly toward the…
Compact elliptical galaxies form a rare class of stellar system (~30 presently known) characterized by high stellar densities and small sizes and often harboring metal-rich stars. They were thought to form through tidal stripping of massive…
We investigated the dynamical structure of 53 elliptical galaxies, based on the {\it Chandra} archival X-ray data. In X-ray luminous galaxies, a temperature increases with radius and a gas density is systematically higher at the optical…
Several Milky Way star clusters show a roughly flat velocity dispersion profile at large radii, which is not expected from models with a tidal cut-off energy. Possible explanations for this excess velocity include: the effects of a dark…
The self-consistent spatial distribution of particles of Galactic dark matter is derived including their own gravitational potential, as also that of the visible matter of the Galaxy. In order to reproduce the observed rotation curve of the…
Observations of density profiles of galaxies and clusters constrain the properties of dark matter. Formation of stable halos by collisional fluids with very low mass particles appears as the most probable interpretation, while halos formed…