Related papers: Diffuse elliptical galaxies, the first 3D spectros…
We present the internal velocity dispersions and spectral line indices for six Virgo ultra-compact dwarf (UCD) galaxies obtained from spectroscopy with the Keck II 10-m telescope. We use these results: 1) to compare the Virgo UCDs with the…
The Universe is now extensively populated by discy galaxies with coherent galaxy-wise stellar rotation. This disc prevalence has been deemed a late-time phenomenon because the penetrating cold gaseous streams in the early Universe…
Dedicated photometric and spectroscopic surveys have provided unambiguous evidence for a strong stellar mass-size evolution of galaxies within the last 10 Gyr. The likely progenitors of today's most massive galaxies are remarkably small,…
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…
From a quantitative analysis of 413 Virgo cluster early-type dwarf galaxies (dEs) with Sloan Digital Sky Survey imaging data, we find that the dE class can be divided into multiple subpopulations that differ significantly in their…
A fraction of early-type dwarf galaxies in the Virgo cluster have a disk component and even possess disk features such as bar, lens, and spiral arms. In this study, we construct 15 galaxy models that resemble VCC856, considered to be an…
It remains challenging to systematically survey nearby diffuse dwarf galaxies and address the formation mechanism of this population distinguishing from regular ones. We carry out a pilot search for these galaxies in the COSMOS field using…
Ultra-compact dwarf galaxies (UCDs) are predominatly found in the cores of nearby galaxy clusters. Besides the Fornax and Virgo cluster, UCDs have also been confirmed in the twice as distant Hydra I and Centaurus clusters. Having (nearly)…
We determine abundance ratios of 37 dwarf ellipticals (dEs) in the nearby Virgo cluster. This sample is representative of the early-type population of galaxies in the absolute magnitude range -19.0 < Mr < -16.0. We analyze their absorption…
The major axis and ellipse-fit intensity profiles of spiral galaxies larger than 0.3'' in the Hubble Space Telescope Ultra Deep Field (UDF) are generally exponential, whereas the major axis profiles in irregular disk galaxies, called…
The fraction of star-forming to quiescent dwarf galaxies varies from almost infinity in the field to zero in the centers of rich galaxy clusters. What is causing this pronounced morphology-density relation? What do quiescent dwarf galaxies…
We present the structural parameters of $\sim910$ dwarf elliptical-like galaxies in the local universe ($z\lesssim0.01$) derived from the $r-$band images of the Sloan Digital Sky Survey (SDSS). We examine the dependence of structural…
By means of interferometic 21-cm observations and a 3D kinematic modeling technique, we study the gas kinematics of six HI-rich ultra-diffuse galaxies (UDGs). We derive robust circular velocities and baryonic masses, that allow us to study…
We present the results of a Keck spectroscopic study of globular clusters associated with the Virgo Cluster dwarf elliptical VCC 1386. We analyze blue spectroscopic absorption lines from 3500-5500 A for 13 globular cluster candidates and…
The structural properties of elliptical galaxies are consistent with their formation in a merging hierarchy. In this picture, the role of gaseous processes and dissipation decreased with increasing mass creating preferentially rotationally…
Galaxy harassment has been proposed as a physical process that morphologically transforms low surface density disc galaxies into dwarf elliptical galaxies in clusters. It has been used to link the observed very different morphology of…
We present the rotation velocities V and velocity dispersions sigma along the principal axes of seven elliptical galaxies less luminous than M_B= -19.5. These kinematics extend beyond the half-light radii for all systems in this…
The starlight coming from the intergalactic space in galaxy clusters and groups witnesses the violent tidal interactions that galaxies experience in these dense environments. Such interactions may be (at least partly) responsible for the…
We use HST/ACS imaging of 100 early-type galaxies in the ACS Virgo Cluster Survey to investigate the nature of diffuse star clusters (DSCs). Compared to globular clusters (GCs), these star clusters have moderately low luminosities (M_V >…
Tests for the intrinsic shape of the luminosity distribution in elliptical galaxies are discussed, with an emphasis on the uncertainties. Recent determinations of the ellipticity frequency function imply a paucity of nearly spherical…