Related papers: Harassment Origin for Kinematic Substructures in D…
We investigated the dynamical reaction of the central region of galaxies to a falling massive black hole by N-body simulations. As the initial galaxy model, we used an isothermal King model and placed a massive black hole at around the…
We have studied a large number of elliptical galaxies and found a correlation between their dark matter content and the ellipticity of their visible shape. The galaxies were strictly selected so that only typical medium-size elliptical…
We review the topic of rotation curves of spiral galaxies emphasizing the standard interpretation as evidence for the existence of dark matter halos. Galaxies other than spirals and late-type dwarfs may also possess great amounts of dark…
We analyze the dark matter (DM) halos of a sample of dwarf Ellitpicals (dE) and discuss cosmological and evolutionary implications. Using orbit modeling we recover their density slopes and, for the first time, the halo flattening. We find…
While galaxy rotation curves provide one of the most powerful methods for measuring dark matter profiles in the inner regions of rotation-supported galaxies, at the dwarf scale there are factors that can complicate this analysis. Given the…
In the standard Lambda cold dark matter paradigm, pure dark matter simulations predict dwarf galaxies should inhabit dark matter haloes with a centrally diverging density `cusp'. This is in conflict with observations that typically favour a…
This article reviews the popular reasons for the belief that dwarf elliptical galaxies and (ordinary) elliptical galaxies are distinct and separate species. They include: light-profile shape (or similarly image concentration); the…
Keck/ESI spectroscopy is presented for six Virgo Cluster dwarf elliptical (dE) galaxies. The mean line-of-sight velocity and velocity dispersion are resolved as a function of radius along the major axis of each galaxy, nearly doubling the…
A homogeneous sample of galaxy redshifts in the core regions (R < 0.5 h$^{-1}$ Mpc) of 12 clusters is used to measure the frequency of substructure with different tests. In 50 % of the cases substructure is detected, a frequency which…
We have simulated disk galaxies undergoing continual bombardment by other galaxies in a rich cluster. "Galaxy harassment" leads to dramatic evolution of smaller disk galaxies and provides an extremely effective mechanism to fuel a central…
We present evidence for kinematically decoupled cores (KDCs) in two dwarf early-type (dE) galaxies in the Virgo cluster, VCC 1183 and VCC 1453, studied as part of the SMAKCED stellar absorption-line spectroscopy and imaging survey. These…
The transformation of late-type galaxies has been suggested as the origin of early-type dwarf galaxies in galaxy clusters. Venhola et al. analysed correlations between colour and surface brightness for galaxies in the Fornax cluster binned…
We present results from an ongoing survey dedicated to the ionized gas kinematics of Virgo cluster spiral galaxies using Fabry-Perot interferometry. Our goal is to study the environmental effects on galaxy evolution in the Virgo cluster. We…
Observations of lopsided spiral galaxies motivated us to explore whether the rapid passage of a companion galaxy could cause them. We examine whether the center of mass of the visible matter becomes displaced from the center of mass of the…
The dwarf galaxies of the Local Group can be separated in three morphological groups: irregular, elliptical and spheroidal. As in the large galaxy clusters, there seems to be a morphology-position relationship: irregular galaxies are…
Recent progress is summarized on the determination of the density distributions of stars and dark matter, stellar kinematics, and stellar population properties, in the extended, low surface brightness halo regions of elliptical galaxies.…
We study the internal response of a galaxy to an unbound encounter and present a survey of orbital parameters covering typical encounters in different galactic environments. Overall, we conclude that relatively weak encounters by low-mass…
Dwarf elliptical galaxies are the most common galaxy type in nearby galaxy clusters, yet they remain relatively poorly studied objects and many of their basic properties have yet to be quantified. In this contribution we present the…
The demographics of dwarf galaxy populations have long been in tension with predictions from the Cold Dark Matter (CDM) paradigm. If primordial density fluctuations were scale-free as predicted, dwarf galaxies should themselves host dark…
We present the first cosmological simulations of dwarf galaxies, which include dark matter self-interactions and baryons. We study two dwarf galaxies within cold dark matter, and four different elastic self-interacting scenarios with…