Related papers: The evolution of stellar structures in dwarf galax…
(Abridged) The formation and evolution of star cluster populations are related to the galactic environment. Cluster formation is governed by processes acting on galactic scales, and star cluster disruption is driven by the tidal field. In…
We investigate the clustering of early-type stars younger than 300 Myr on galactic scales in M31. Based on the stellar photometric catalogs of the Panchromatic Hubble Andromeda Treasury program that also provides stellar parameters derived…
We present NIR and MIR observations of eight embedded young stellar groups around Herbig Ae/Be stars (HAEBEs) using archived Spitzer IRAC data and 2MASS data. These young stellar groups are nearby ($\leq$ 1 kpc) and still embedded within…
The evolution of star clusters is determined by several internal and external processes. Here we focus on two dominant internal effects, namely energy exchange between stars through close encounters (two-body relaxation) and mass-loss of…
(Abridged) Age derivation techniques for unresolved stellar populations at high redshifts are explored using the NUV spectrum of LBDS~53W091 and LBDS~53W069. The photometry and morphology of these galaxies suggest they are early-type…
In systems undergoing starbursts the evolution of the young stellar population is expected to drive changes in the emission line properties. This evolution is usually studied theoretically, with a combination of evolutionary synthesis…
The details of bulge formation via collapse, mergers, secular processes or their interplay remain unresolved. To start answering this question and quantify the importance of distinct mechanisms, we mapped a sample of three galactic bulges…
Determining the properties of old stellar populations (those with age >1 Gyr) has long involved the comparison of their integrated light, either in the form of photometry or spectroscopic indexes, with empirical or synthetic templates. Here…
New deep optical and near-infrared imaging is combined with archival ultraviolet and infrared data for fifteen nearby galaxies mapped in the Spitzer Extended Disk Galaxy Exploration Science survey. These images are particularly deep and…
Observational evidence has been mounting over the past decade that at least some luminous (~2 L*) galaxies have formed nearly all of their stars within a short period of time only 1-2x10^9 years after the Big Bang. These are examples of the…
We present the first results of a new technique to detect, locate, and characterize young dissolving star clusters. Using HST/ACS archival images of the nearby galaxy IC2574, we performed stellar PSF photometry and selected the most massive…
What can we learn from the somewhat arduous study of old stellar populations in nearby galaxies? Unless the nearby universe is subtly anomalous, it should contain a relatively normal selection of galaxies whose histories are representative…
We investigate recent star formation in the extended ultraviolet (XUV) disks of five nearby galaxies (NGC 0628, NGC 2090, NGC 2841, NGC 3621, and NGC 5055) using a long wavelength baseline comprised of ultraviolet and mid-infrared imaging…
Substellar multiplicity is a key outcome of the formation process. The biggest challenge for the next decade will be to distinguish between the formation history, environmental conditions, and dynamical evolution leading to the least…
We have examined the stellar structure of 10 nearby, low stellar mass (10^6 to 6 x 10^7 Msolar) dwarf irregular galaxies by fitting ellipses as a function of surface brightness on ultra-deep V images. These are compared to far ultraviolet…
We use detailed modeling of stellar populations of nearby galaxies to calculate population parameters. Our sample of galaxies includes most galaxies of the Local Group and several more distant giant galaxies. Available data are sufficient…
We present a detailed spatial analysis of stellar populations based on long-slit optical spectra in a sample of eight luminous early-type galaxies selected from nearby sparse groups and pairs, three of them may be interacting with a galaxy…
We study the ages of $\alpha$-rich and $\alpha$-poor stars in the halo using a sample of F and G dwarfs from the Sloan Digital Sky Survey (SDSS). To separate stars based on [$\alpha$/Fe], we have developed a new semi-empirical…
We have constructed a family of simple models for spiral galaxy evolution to allow us to investigate observational trends in star formation history with galaxy parameters. The models are used to generate broad band colours from which ages…
We present results from an analysis of stellar population parameters for 7132 galaxies in the 6dFGS Fundamental Plane (FP) sample. We bin the galaxies along the axes, $v_1$, $v_2$, and $v_3$, of the tri-variate Gaussian to which we have fit…