Related papers: Stellar Crowding and the Science Case for Extremel…

One of the highlights of the European ELT Science Case book is the study of resolved stellar populations, potentially out to the Virgo Cluster of galaxies. A European ELT would enable such studies in a wide range of unexplored distant…

We investigate the multiple stellar populations of the globular clusters M3, M5, M13, and M71 using $g^\prime$ and intermediate-band CN-$\lambda 3883$ photometry obtained with the WIYN 0.9-m telescope on Kitt Peak. We find a strong…

Current efforts in observational cosmology are focused on characterizing the mass-energy content of the Universe. We present results from a geometric test based on strong lensing in galaxy clusters. Based on Hubble Space Telescope images…

We investigate the effects of potential sources of systematic error on the angular and photometric redshift, z_phot, distributions of a sample of redshift 0.4 < z < 0.7 massive galaxies whose selection matches that of the Baryon Oscillation…

We evaluate the impact of imaging systematics on the clustering of luminous red galaxies (LRG), emission-line galaxies (ELG) and quasars (QSO) targeted for the upcoming Dark Energy Spectroscopic Instrument (DESI) survey. Using Data Release…

The suggestion by Zaritsky & Lin that a vertical extension of the red clump feature in color-magnitude diagrams of the Large Magellanic Cloud (LMC) is consistent with a significant population of foreground stars to the LMC that could…

Stellar intensity interferometers will achieve stellar imaging with a tenth of a milli- arcsecond resolution in the optical band by taking advantage of the large light collect- ing area and broad range of inter-telescope distances offered…

By stacking an ensemble of strong lensing clusters, we demonstrate the feasibility of placing constraints on the dark energy equation of state. This is achieved by using multiple images of sources at two or more distinct redshift planes.…

The central region of the Virgo cluster of galaxies contains thousands of globular clusters (GCs), an order of magnitude more than the numbers found in the Local Group. Relics of early star formation epochs in the universe, these GCs also…

The stellar scintillation is one of the fundamental limitation to the precision of ground-based photometry. The paper examines the problem of correlation of the scintillation of two close stars at the focus of a large telescope. The derived…

Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty…

(abridged) We present the first results of our deep survey of lensing clusters aimed at constraining the abundance of star-forming galaxies at z~6-10. Deep near-IR photometry of two lensing clusters (A1835 and AC114) was obtained with…

We forecast constraints on the amplitude of matter clustering sigma_8(z) achievable with the combination of cluster weak lensing and number counts, in current and next-generation weak lensing surveys. We advocate an approach, analogous to…

We use giga-particle N-body simulations to study galaxy cluster populations in Hubble Volumes of LCDM (Omega_m=0.3, Omega_Lambda=0.7) and tCDM (Omega_m=1) world models. Mapping past light-cones of locations in the computational space, we…

We present BVI CCD photometry for more than 10,000 stars in the innermost region (0.3' < r <~ 4') of the globular cluster M 3. When added to the previous photographic photometry by Buonanno et al. (1994) reaching as far as r ~ 7', this…

Strongly lensed star clusters have recently been detected up to redshift $z\approx 10$ in galaxy cluster fields using the James Webb Space Telescope (JWST). When pairs of mirror images of such star clusters appear across the lensing…

The existence of star-to-star light-element abundance variations in massive Galactic and extragalactic star clusters has fairly recently superseded the traditional paradigm of individual clusters hosting stars with the same age, and uniform…

The possibility to constrain cosmological parameters from galaxy surveys using field-level machine learning methods that bypass traditional summary statistics analyses, depends crucially on our ability to generate simulated training sets.…

Galaxy cluster mergers are a powerful laboratory for testing cosmological and astrophysical models. However, interpreting individual merging clusters depends crucially on their merger configuration, defined by the masses, velocities, impact…

We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar-neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into account the…