Related papers: From star clusters to dwarf galaxies: The properti…
We examine the dynamics of the stars and globular clusters in the nearby giant galaxy M87 and constrain the mass distribution, using all the available data over a large range of radii, including higher-order moments of the stellar…
Giant star-forming clumps are a prominent feature of star-forming galaxies (SFGs) and contain important clues on galaxy formation and evolution. However, basic demographics of clumps and their host galaxies remain uncertain. Using the…
As part of the HST/ACS Coma Cluster Treasury Survey, we have undertaken a Keck/LRIS spectroscopic campaign to determine membership for faint dwarf galaxies. In the process, we discovered a population of Ultra Compact Dwarf galaxies (UCDs)…
We present a study of the properties of the star-cluster systems around pseudo-bulges of late-type spiral galaxies using a sample of 11 galaxies with distances from 17 to 37 Mpc. Star clusters are identified from multiband HST ACS and WFPC2…
Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in a wide range of environments. Studies of the internal dynamics and dark matter content of UDGs…
We present BVI photometry of 190 galaxies in the central region of the Fornax Cluster observed with the Michigan Curtis Schmidt Telescope. The cluster members exhibit a strong surface brightness-magnitude relation in our data: both giant…
Recent photometric observations by the {\it Hubble Space Telescope (HST)} have revealed the physical properties of stellar galactic nuclei in nucleated dwarf galaxies in the Virgo cluster of galaxies. In order to elucidate the formation…
We calculated the median values of the following parameters for 87 groups of galaxies with three to eight components: the mean rms velocity of the galaxies in the group, S_v = 166 km/s; the harmonic mean radius, R_h = 29 kpc; and the…
The recent discovery of thousands of ultra diffuse galaxies (UDGs) in nearby galaxy clusters has opened a new window into the process of galaxy formation and evolution. Several scenarios have been proposed to explain the formation history…
Scaling relations for globular clusters (GC) differ from scaling relations for pressure supported (elliptical) galaxies. We show that two-body relaxation is the dominant mechanism in shaping the bivariate dependence of density on mass and…
The total mass M_GCS in the globular cluster (GC) system of a galaxy is empirically a near-constant fraction of the total mass M_h = M_bary + M_dark of the galaxy, across a range of 10^5 in galaxy mass. This trend is radically unlike the…
Ultra-Diffuse Galaxies are both extreme products of galaxy evolution and extreme environments in which to test our understanding of star formation. In this work, we contrast the spatially resolved star formation activity of a sample of 22…
We review observational data about a sample of Local Volume objects containing about 1000 galaxies within 11 Mpc of the Milky Way. Dwarf galaxies with stellar masses $M_*/M_{\odot} < 9$ dex make up 5/6 of the sample. Almost 40% of them have…
Two competing theories posit that Ultra Compact Dwarfs (UCDs) form either as the stripped nuclei of dwarf galaxies or as giant globular clusters (GGCs) associated with the largest globular cluster (GC) systems. By focussing on the field and…
I compare the dark matter content within stellar half-mass radius expected in a $\Lambda$CDM-based galaxy formation model with existing observational estimates for the observed dwarf satellites of the Milky Way and ultra-diffuse galaxies…
We study the UV properties of a volume limited sample of early-type galaxies in the Virgo cluster combining new GALEX far- (1530 A) and near-ultraviolet (2310 A) data with spectro-photometric data available at other wavelengths. The sample…
We use data from the first epoch of observations with the IRAC/Spitzer for the GOODS to detect and study a collection of LBGs at z ~ 6 to 5 in the HUDF, six of which have spectroscopic confirmation. At these redshifts, IRAC samples…
It has been 10 years since the initial discovery of Ultra-Diffuse Galaxies (UDGs) in the Coma cluster and the revelation that large, low surface brightness galaxies may constitute a greater fraction of galaxies than first thought. This left…
We present Halpha narrow-band imaging of 17 dwarf irregular galaxies (dIs) in the nearby Centaurus A Group. Although all large galaxies of the group have a current or recent enhanced star formation episode, the dIs have normal star…
We present a detailed analysis of two-band HST/ACS imaging of 21 ultra-compact dwarf (UCD) galaxies in the Virgo and Fornax Clusters. The aim of this work is to test two formation hypotheses for UCDs--whether they are bright globular…