M. Makler

EIGHT NEW MILKY WAY COMPANIONS DISCOVERED IN FIRST-YEAR DARK ENERGY SURVEY DATA

We report the discovery of eight new Milky Way companions in ~1,800 deg^2 of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (M_V from -2.2 mag to -7.4 mag), physical sizes (10 pc to 170 pc), and heliocentric distances (30 kpc to 330 kpc). Based on the low surface brightnesses, large physical sizes, and/or large Galactocentric distances of these objects, several are likely to be new ultra-faint satellite galaxies of the Milky Way and/or Magellanic Clouds. We introduce a likelihood-based algorithm to search for and characterize stellar over-densities, as well as identify stars with high satellite membership probabilities. We also present completeness estimates for detecting ultra-faint galaxies of varying luminosities, sizes, and heliocentric distances in the first-year DES data.

Constraints on the generalized Chaplygin gas from supernovae observations

Abstract We explore the implications of type Ia supernovae (SNIa) observations on flat cosmological models whose matter content is an exotic fluid with equation of state, p =− M 4( α +1) / ρ α . In this scenario, a single fluid component may drive the Universe from a nonrelativistic matter dominated phase to an accelerated expansion phase behaving, first, like dark matter and in a more recent epoch as dark energy. We show that these models are consistent with current SNIa data for a rather broad range of parameters. However, future SNIa experiments will place stringent constraints on these models, and could safely rule out the special case of a Chaplygin gas ( α =1) if the Universe is dominated by a true cosmological constant.

Photometric redshift analysis in the Dark Energy Survey science verification data

We present results from a study of the photometric redshift performance of the Dark Energy Survey (DES), using the early data from a Science Verification (SV) period of observations in late 2012 and early 2013 that provided science-quality images for almost 200 sq.~deg.~at the nominal depth of the survey. We assess the photometric redshift performance using about 15000 galaxies with spectroscopic redshifts available from other surveys. These galaxies are used, in different configurations, as a calibration sample, and photo-

Observational constraints on Chaplygin quartessence: Background results

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Automated transient identification in the Dark Energy Survey

s are obtained and studied using most of the existing photo-

First measurement of the cross-correlation of CMB lensing and galaxy lensing

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Mass and galaxy distributions of four massive galaxy clusters from Dark Energy Survey Science Verification data

codes. A weighting method in a multi-dimensional color-magnitude space is applied to the spectroscopic sample in order to evaluate the photo-

Cosmological constraints from weak lensing peak statistics with Canada-France-Hawaii Telescope Stripe 82 Survey

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Weak lensing mass map and peak statistics in Canada–France–Hawaii Telescope Stripe 82 survey

performance with sets that mimic the full DES photometric sample, which is on average significantly deeper than the calibration sample due to the limited depth of spectroscopic surveys. Empirical photo-

MODELING THE TRANSFER FUNCTION FOR THE DARK ENERGY SURVEY

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