Related papers: Starbursting Nuclei in Old Dwarf Galaxies
Nuclear star clusters (NSCs) are the densest stellar systems in the Universe. They can be found at the center of all galaxy types, but tend to favor galaxies of intermediate stellar mass around 10$^9\,$M$_{\odot}$[1, 2]. Currently, two main…
In this paper we study the underlying stellar population of a sample of 65 nearby early-type galaxies predominantly located in low density environments. Ages, metallicities and [alpha/Fe] ratios have been derived through the comparison of…
Star cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent starbursts. Young clusters are observed to form in a variety of such galaxies, a substantial number resembling the…
We analyse multi-wavelength Hubble Space Telescope (HST) observations of a large number of star clusters in the nearby (post-) starburst dwarf galaxy NGC 1569. Their spectral energy distributions (SEDs) cover at least the wavelength range…
The empirical model of Lu et al. 2014 is updated with recent data and used to study galaxy star formation and assembly histories. At $z > 2$, the predicted galaxy stellar mass functions are steep, and a significant amount of star formation…
The presence of transitional dwarf galaxies in filaments and cluster outskirts may be closely related to pre-processing in the filament; however, the underlying mechanism is not yet comprehensively understood. We present the spatially…
We present the results of a Hubble Space Telescope WFPC2 F555W and F814W survey of 69 dwarf elliptical galaxies (dEs) in the Virgo and Fornax Clusters and Leo Group. The $V-I$ colors of the dE globular clusters, nuclei, and underlying field…
We investigate the star formation histories (SFHs) of 983 early-type dwarf galaxies classified into five morphological subtypes, dS0, dE, dEbc, dSph, and dEbl,across six environments ranging from the field to rich clusters such as Ursa…
The ability of HST to resolve objects ten times smaller than possible from the ground has rejuvenated the study of young star clusters. A recurrent morphological theme found in nearby resolved sytems is the observation of young (typically 1…
Over the last decade, HST imaging studies have revealed that the centers of most galaxies are occupied by compact, barely resolved sources. Based on their structural properties, position in the fundamental plane, and spectra, these sources…
We use the spectra of ~ 22,000 early-type galaxies, selected from the Sloan Digital Sky Survey, to infer the ages, metallicities and star formation histories of these galaxies. We find clear evidence of "downsizing", i.e. galaxies with…
We present an analysis of 39 nuclei and their early-type hosts in the Virgo Cluster using ten broadband filters: F300W, F475W, F850LP, F160W, $u^*griz$, and $K_s$. We describe the Virgo Redux program, which provides high-resolution UV and…
We review the current knowledge about nuclear star clusters (NSCs), the spectacularly dense and massive assemblies of stars found at the centers of most galaxies. Recent observational and theoretical work suggest that many NSC properties,…
We use a purely data-driven rectified factor analysis to identify early-type galaxies with recent star formation in DR4 of the SDSS Spectroscopic Catalogue. We compare the spectra and environment of these galaxies with `normal' early-types,…
(Abridged) The ACS Virgo Cluster Survey is an HST program to obtain high-resolution, g and z-band images for 100 early-type members of the Virgo Cluster, spanning a range of ~460 in blue luminosity. Based on this large, homogeneous dataset,…
We present a study of the variation of spatial structure of stellar populations within dwarf galaxies as a function of the population age. We use deep Hubble Space Telescope/Advanced Camera for Surveys imaging of nearby dwarf galaxies in…
As a result of bidimensional spectroscopy of the central parts of two nearby lenticular galaxies, NGC 1023 and NGC 7332, undertaken with the Multi-Pupil Field Spectrograph of the 6m telescope of the Special Astrophysical Observatory, their…
Ultra compact dwarf galaxies (UCDs) have similar properties as massive globular clusters or the nuclei of nucleated galaxies. Recent observations suggesting a high dark matter content and a steep spatial distribution within groups and…
We present optical and near-infrared colour maps of the central regions of bulges of S0 and spiral galaxies obtained with WFPC2 and NICMOS on the HST. By combined use of HST and ground-based data the colour information spans from a few tens…
The specific globular cluster frequencies (S_N) for 24 dwarf elliptical (dE) galaxies in the Virgo and Fornax Clusters and the Leo Group imaged with the Hubble Space Telescope are presented. Combining all available data, we find that for…