The Dark Energy Survey: Status and First results

Abstract

The observational results of the latest 15 to 20 years have stablished a standard model for the cosmology which has some amazing consequences. A mysterious entity, the dark energy, has been confirmed as the dominant component of the Universe, and is also responsible for its accelerated expansion. However, its physical nature remains unknown. Unveiling the nature of the dark energy is one of the main problems of cosmology. A powerful way of studying this problem is the measurement of different and complementary probes of the dark energy in very large galaxy surveys. The Dark Energy Survey (DES) is an optical and near infrared survey that is imaging 5000 deg2 of the southern celestial hemisphere in five broad bandpass filters, to study the properties of this mysterious dark energy. In order to perform such a survey, a new CCD camera of 3 deg2 field of view has been mounted on the Blanco 4m telescope at Cerro Tololo (Chile). The survey observations started in 2012, with the science verification run. DES will study the dark energy properties using four independent methods: galaxy clusters counts and distributions, weak gravitational lensing tomography, baryon acoustic oscillations and supernovae Ia distances. Obtaining the four measurements from the same data set will allow a strict control of the systematic uncertainties to obtain a robust and precise determination of the cosmological parameters. Here, the first scientific results of the project, based on science verification data and related to photometric redshifts and galaxy shape measurements, are presented.