Related papers: The Mass Function of the Arches Cluster from Gemin…
The mass function of galaxies and clusters of galaxies can be derived observationally based on different types of observations. In this study we test if these observations can be combined to a consistent picture which is also in accord with…
We present the stellar mass functions (SMFs) of star-forming and quiescent galaxies from observations of 10 rich clusters in the Gemini Cluster Astrophysics Spectroscopic Survey (GCLASS) in the redshift range 0.86<z<1.34. We compare our…
We present the results of the analysis of deep photometric data of 32 Galactic globular clusters. We analysed 69 parallel field images observed with the Wide Field Channel of the Advanced Camera for Surveys of the Hubble Space Telescope…
Context. We use Hubble Space Telescope photometry of six rich, compact star clusters in the Large Magellanic Cloud (LMC), with ages ranging from 0.01 to 1.0 Gyr, to derive the clusters' stellar mass functions (MFs) at their half-mass radii.…
The stellar initial mass function (IMF) in star clusters is reviewed. Uncertainties in the observations are emphasized. We suggest there is a distinct possibility that cluster IMFs vary systematically with density or pressure. Dense…
The Quintuplet and Arches clusters, which were formed in the harsh environment of the Galactic Center (GC) a few million years ago, have been excellent targets for studying the effects of a star-forming environment on the initial mass…
The evolution of the cluster mass function and the cluster correlation function from z = 0 to z = 3 are determined using 10^6 clusters obtained from high-resolution simulations of the current best-fit LCDM cosmology (\Omega_m = 0.27,…
We present a comprehensive investigation on the mass function (MF) of a snake-like stellar structure in the solar neighbourhood, building on our previous discovery. To ensure the reliability of the data, we reselect the member stars of the…
We employ a large sample of 20171 optically-selected groups and clusters at 0.15 < z < 0.4 in the SDSS to investigate how the stacked stellar mass fraction varies across a wide range of total mass, $M_{500}$. Our study improves upon…
We have observed two of the six Frontier Fields galaxy clusters, MACS J0416.1-2403 and Abell 2744, using the Gemini Multi-Conjugate Adaptive Optics System (GeMS) and the Gemini South Adaptive Optics Imager (GSAOI). With 0.08"-0.10" FWHM our…
Observations of Galactic star clusters and objects in nearby moving groups recorded with Adaptive Optics (AO) systems on Gemini South are discussed. These include observations of open and globular clusters with the GeMS system, and high…
We analyze line-of-sight velocity and proper motion data of stars in the Galactic globular cluster M15 using a new method to fit dynamical models to discrete kinematic data. Our fitting method maximizes the likelihood for individual stars…
We present the composite luminosity function (hereafter LF) of galaxies for 80 Abell clusters studied in our survey of the Northern Hemisphere, using DPOSS data in the framework of the CRoNaRio collaboration. Our determination of the LF has…
We present measurements of the angular correlation function of galaxies selected from the first field of the H-ATLAS survey. Careful removal of the background from galactic cirrus is essential, and currently dominates the uncertainty in our…
We used Early Release Science (ERS) observations taken with the Wide Field Camera 3 (WFC3) in the GOODS-S field to study the galaxy stellar mass function (GSMF) at 0.6<=z<4.5. Deep WFC3 near-IR data (for Y as faint as 27.3, J and H as faint…
The gravitational lens effect of galaxy clusters can produce large arcs from source galaxies in their background. Typical source redshifts of ~ 1 require clusters at z ~ 0.3 for arcs to form efficiently. Given the cluster abundance at the…
Massive halos hosting groups and clusters of galaxies imprint coherent, arcminute-scale features across the spectrophotometric sky, especially optical-IR clusters of galaxies, distortions in the sub-mm CMB, and extended sources of X-ray…
We perform a flexion based weak gravitational analysis of the first two Hubble Frontier Field clusters: Abell 2744 and MACS 0416. A parametric method for using projected flexion signals as a probe of cluster member mass is described in…
High-precision HST photometry has recently revealed that the globular cluster (GC) NGC 2808 hosts a triple main sequence (MS) corresponding to three stellar populations with different helium abundances. We carried out photometry on ACS/WFC…
We present V and I equivalent HST/WFPC2 photometry of two areas in the Large Magellanic Cloud: The southern part of the stellar association LH 52, located on the western edge of the super-shell LMC 4, and a field between two associations,…