Related papers: Halo Kinematics
Based on a uniform dynamical analysis of line-profile shapes for 21 luminous round elliptical galaxies, we have investigated the dynamical family relations of ellipticals: (i) The circular velocity curves (CVCs) of elliptical galaxies are…
Context. The assembly history of the stellar component of a massive elliptical galaxy is closely related to that of its dark matter halo. Measuring how the properties of galaxies correlate with their halo mass can help understand their…
Observations indicate that the baryonic matter of galaxies is surrounded by vast dark matter halos, which nature remains unknown. This document details the analysis of the results published in MNRAS 438, 2, 1535 (2014) reporting an…
We use numerical simulations to examine the substructure within galactic and cluster mass halos that form within a hierarchical universe. Clusters are easily reproduced with a steep mass spectrum of thousands of substructure clumps that…
We describe a non-parametric method for determining both the anisotropy and mass profiles of elliptical galaxies from velocity dispersions and velocity profile shapes along the line of sight. In this way, mass-to-light ratios out to 2-3…
Dynamical modeling and strong lensing data indicate that the total density profiles of early-type galaxies are close to isothermal, i.e., rho_tot ~ r^gamma with gamma approx -2. To understand the origin of this universal slope we study a…
Large samples of Field Horizontal Branch (FHB) stars make excellent tracers of the Galactic halo; by studying their kinematics, one can infer important physical properties of our Galaxy. Here we present the results of a medium-resolution…
A review of the present observational and theoretical status of elliptical galaxies is presented with the aim to clarify whether the monolithic or the hierarchical, is a more viable scenario for the origin of these structures. We describe…
We present harmonic decompositions of the velocity fields of 19 galaxies from THINGS (The \HI Nearby Galaxy Survey) which quantify the magnitude of the non-circular motions in these galaxies and yield observational estimates of the…
Several proposed models for dark matter posit the existence of self-interaction processes that can impact the shape of dark matter halos, making them more spherical than the ellipsoidal halos of collisionless dark matter. One method of…
The kinematic and dynamical properties of galaxy stellar halos are difficult to measure because of the faint surface brightness that characterizes these regions. Spiral galaxies can be probed using the radio HI emission; on the contrary,…
The last decade of research on elliptical galaxies has produced a wealth of new information concerning both their detailed structure and their global scaling relations. We review the old and new results about isophote shapes and…
Globular clusters have proven to be essential to our understanding of many important astrophysical phenomena. Here we analyse spectroscopic observations of ten Halo globular clusters to determine their dark matter content, their tidal…
Many of the fundamental properties of early-type galaxies (ellipticals and lenticulars) can only be accessed by venturing beyond their oft-studied centers into their large-radius halo regions. Advances in observations of kinematical tracers…
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;…
I present various projects to study the halo dynamics of elliptical galaxies. This allows one to study the outer mass and orbital distributions of ellipticals in different environments, and the inner distributions of groups and clusters…
The balance of evidence indicates that individual galaxies and groups or clusters of galaxies are embedded in enormous distributions of cold, weakly interacting dark matter. These dark matter 'halos' provide the scaffolding for all luminous…
Without the interference of a number of events, galaxies may suffer in crowded environments (e.g., stripping, harassment, strangulation); isolated elliptical galaxies provide a control sample for the study of galaxy formation. We present…
A new kinematic and dynamic study of the halo of the giant elliptical galaxy, NGC 5128, is presented. From a spectroscopically confirmed sample of 340 globular clusters and 780 planetary nebulae, the rotation amplitude, rotation axis,…
We report on ongoing photometric and spectroscopic work on a sample of isolated elliptical galaxies. We investigate their globular cluster systems, and use the kinematics of globular clusters and the integrated galaxy light to constrain…