相关论文: The First Generation of Virgo Cluster Dwarf Ellipt…
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…
Abridge. We have conducted a spectrophotometric study of dwarf early-type galaxies (dEs) in the Virgo cluster and in regions of lower density. We have found that these galaxies show many properties in common with late-type galaxies but not…
We present new medium resolution kinematic data for a sample of 21 dwarf early-type galaxies (dEs) mainly in the Virgo cluster, obtained with the WHT and INT telescopes at the Roque de los Muchachos Observatory (La Palma, Spain). These data…
Dwarf elliptical galaxies (dEs) are the dominant population in galaxy clusters and serve as ideal probes for studying the environmental impact on galactic evolution. A substantial fraction of dEs are known to harbor central nuclei, which…
We show the effects of environmental evolution on Virgo cluster and field dwarf elliptical galaxies (dEs), presenting the first large-scale integral-field spectroscopic data for this galaxy class. The great variety of morphological,…
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…
Despite the common picture of an early-type dwarf (dE) as a quiescent galaxy with no star formation and little gas, we identify 23 dEs that have blue central colors caused by recent or ongoing star formation in our sample of 476 Virgo…
What happens to dwarf galaxies as they enter the cluster potential well is one of the main unknowns in studies of galaxy evolution. Several evidence suggests that late-type galaxies enter the cluster and are transformed to dwarf early-type…
We present spatially-resolved internal kinematics and stellar chemical abundances for a sample of dwarf elliptical (dE) galaxies in the Virgo Cluster observed with Keck/ESI. We find that 4 out of 17 dEs have major axis rotation velocities…
We analyse the stellar structure of a sample of dwarf ellipticals (dE) inhabiting various environments within the Virgo cluster. Integral-field observations with a high spectral resolution allow us to robustly determine their low velocity…
Early-type dwarfs are the most common galaxy in the local universe, yet their origin and evolution remain a mystery. Various cosmological scenarios predict that dwarf-like galaxies in dense areas are the first to form and hence should be…
New observations of 16 dwarf elliptical galaxies in the Virgo Cluster indicate that at least seven dEs have significant velocity gradients along their optical major axis, with typical rotation amplitudes of 20-30 km/s. Of the remaining nine…
Understanding the origin and evolution of dwarf early-type galaxies remains an important open issue in modern astrophysics. Internal kinematics of a galaxy contains signatures of violent phenomena which may have occurred, e.g. mergers or…
We analyze the stellar kinematics of 39 dwarf early-type galaxies (dEs) in the Virgo cluster. Based on the specific stellar angular momentum lambda_e and the ellipticity, we find 11 slow rotators and 28 fast rotators. The fast rotators in…
Recent observations demonstrate that dwarf elliptical (dE) galaxies in clusters, despite their faintness, are likely a critical galaxy type for understanding the processes behind galaxy formation. Dwarf ellipticals are the most common…
Early-type dwarfs (dEs) are by far the most abundant galaxy population in nearby clusters. Whether these objects are primordial, or the recent end-products of the different physical mechanisms that can transform galaxies once they enter…
The presence of blue cores in some dwarf early-type galaxies (dEs) in galaxy clusters suggests the scenario of late-type galaxy infall and subsequent transformation into red, quiescent dEs. We present Gemini Multi-Object Spectrographs…
We present UBVRI surface photometry for 16 dwarf elliptical galaxies in the Virgo Cluster with previously measured kinematic properties. The global optical colors are red, with median values for the sample of 0.24 +/- 0.03 in (U-B), 0.77…
This thesis presents observational studies of evolution of dwarf elliptical galaxies. dE's are numerically dominant population in clusters of galaxies, but their origin and evolution is a matter of debate. Several scenarios of gas removal…
We present a systematic search for disks in 476 Virgo cluster early-type dwarf (dE) galaxies. Disk features (spiral arms, edge-on disks, or bars) were identified by applying unsharp masks to a combined image from three bands (g, r, i), as…