Related papers: Deep Astrometric Standards (DAS) and Galactic Stru…
We describe the scientific motivation behind, and the methodology of, the Stanford Cluster Search (StaCS), a program to compile a catalog of optically selected clusters of galaxies at intermediate and high (0.3 < z < 1) redshifts. The…
We outline here the next generation of cluster-finding algorithms. We show how advances in Computer Science and Statistics have helped develop robust, fast algorithms for finding clusters of galaxies in large multi-dimensional astronomical…
The promise of multi-wavelength astronomy has been tempered by the large disparity in sensitivity and resolution between different wavelength regimes. Here we present a statistical approach which attempts to overcome this by fitting…
The COSMOS field has been the subject of a wide range of observations, with a number of studies focusing on reconstructing the 3D dark matter density field. Typically, these studies have focused on one given method or tracer. In this paper,…
DARTS search space (DSS) has become a canonical benchmark for NAS whereas some emerging works pointed out the issue of narrow accuracy range and claimed it would hurt the method ranking. We observe some recent studies already suffer from…
The existence of a spatially thin, kinematically coherent Disk of Satellites (DoS) around the Milky Way (MW), is a problem that often garners vivacious debate in the literature or at scientific meetings. One of the most recent incarnations…
We analyse a 10,000 star spectroscopic survey, focused on Galactic thick disk stars typically 2-5 kpc from the Sun, carried out using the AAOmega Spectrograph on the AAT. We develop methods for completeness-correction of the survey based on…
I first review the status of Digital Sky Surveys. The focus will be on extragalactic surveys with an area of more than 100 sq.deg. The Sloan Digital Sky Survey is the archetype of such imaging surveys and it is its great success that has…
The goal of this survey is to study the formation and evolution of the Milky Way halo to deduce its assembly history and the 3D distribution of mass in the Milky Way. The combination of multi-band photometry, Gaia proper motion and parallax…
The era of the next generation of giant telescopes requires not only the advent of new technologies but also the development of novel methods, in order to exploit fully the extraordinary potential they are built for. Global Multi Conjugate…
Galaxy masses can be estimated by a variety of methods; each applicable in different circumstances, and each suffering from different systematic uncertainties. Confirmation of results obtained by one technique with analysis by another is…
CONTEXT. Massive stars have high-multiplicity fractions, and many of them have still undetected components, thus hampering the study of their properties. AIMS. I study a sample of massive stars with high angular resolution to better…
Based on SDSS and South Galactic Cap of u-band Sky Survey (SCUSS) early data, we use star counts method to estimate the Galactic structure parameters in an intermediate latitude with 10,180 main-sequence (MS) stars in absolute magnitude…
We use extensive gravity-sensitive DDO 51 photometry over 5100 square degrees, combined with SDSS broadband photometry, to select a catalog of $\sim 4,000$ giant stars covering a large fraction of the high Galactic latitude sky and reaching…
Stringent observational constraints on the sub-galactic matter power spectrum would allow one to distinguish between the concordance $\Lambda$CDM and the various alternative dark-matter models that predict significantly different properties…
Using effective temperature and metallicity derived from SDSS spectra for ~60,000 F and G type main sequence stars (0.2<g-r<0.6), we develop polynomial models for estimating these parameters from the SDSS u-g and g-r colors. We apply this…
The discovery of Ultra-Faint Dwarf (UFD) galaxies in the halo of the Milky Way extends the faint end of the galaxy luminosity function to a few hundred solar luminosities. This extremely low luminosity regime poses a significant challenge…
Recent large-scale galaxy spectroscopic surveys, such as the Sloan Digital Sky Survey (SDSS), enable us to execute a systematic, relatively-unbiased search for galaxy clusters. Such surveys make it possible to measure the 3-d distribution…
Magnification bias, the lensing-induced modification of background source number counts, provides a uniquely powerful probe of the mass density profiles of galaxies and clusters down to kpc scales. Unlike shear-based weak lensing,…
Exoplanets have sparked interest in extremely high signal-to-noise ratio spectroscopic observations of very bright stars, in a regime where flux calibrators, in particular DA white dwarfs, are not available. We argue that A-type stars offer…