Prof. David Alonso

Abstract:

We propose a novel method for the extraction of the baryonic acoustic oscillation scale in galaxy photometric surveys. The evolution of this scale can be used as a standard ruler in order to constrain cosmological parameters. The method consists in parametrize the angular correlation function ω(θ), with a simple analitical expresion, in order to extract the sound horizon scale. The method has been tested in the MICE simulation, one of the largest N-body simulation to date. We have considered projection effects, non-linearities and observational effects in our analysis, obtaining errors in cosmological parameters in agreement with what is expected in new generation surveys.

Abstract:

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system designed to obtain multiple images covering the sky visible from Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. This system can image about 10,000 square degrees of sky in three clear nights using pairs of 15-second exposures twice per night, with typical 5$\sigma$ depth for point sources of $r\sim24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.