DES Collaboration

DES Collaboration
Name	Dark Energy Survey Collaboration
Formed	2004
Headquarters	Cerro Tololo Inter-American Observatory
Leader title	Director
Leader name	Edward "Rocky" Kolb

DES Collaboration

The DES Collaboration is an international consortium formed to carry out the Dark Energy Survey using the Victor M. Blanco Telescope at Cerro Tololo Inter-American Observatory. It unites institutions such as the Fermi National Accelerator Laboratory, Lawrence Berkeley National Laboratory, University of Chicago, University of Cambridge, and ETH Zurich to investigate cosmological acceleration, structure formation, and galaxy evolution. The project integrates expertise from experiments like the Sloan Digital Sky Survey, the Dark Energy Spectroscopic Instrument, and the Large Synoptic Survey Telescope precursor efforts.

Overview

The collaboration was established in 2004 with members from national laboratories, universities, and observatories including SLAC National Accelerator Laboratory, University of Michigan, University of Pennsylvania, University of Portsmouth, and Pontificia Universidad Católica de Chile. The survey executed observations from 2013 to 2019 using the Blanco 4-meter Telescope and the DECam imager, producing imaging data across five photometric bands to map large-scale structure, weak lensing, galaxy clusters, and supernovae. Governance includes a collaboration board with representatives from institutes such as Fermilab, Kavli Institute for Cosmological Physics, Institut d'Astrophysique de Paris, and Max Planck Institute for Astronomy.

Scientific Objectives and Research

DES aims to constrain parameters of the Lambda-CDM model and alternatives such as quintessence and modified gravity proposals by measuring the equation of state of dark energy, the growth rate of cosmic structure, and the geometry of the universe. Science working groups focus on weak gravitational lensing analyses akin to studies from Hubble Space Telescope, baryon acoustic oscillation measurements in the spirit of BOSS, cluster abundance comparisons to Planck (spacecraft) results, and Type Ia supernova cosmology tied to the Supernova Legacy Survey. Cross-correlation projects connect DES results with data from South Pole Telescope, Gaia (spacecraft), and WISE to improve photometric redshifts and mitigate systematics.

Instrumentation and Survey Design

Instrumentation centers on the Dark Energy Camera (DECam), a 570-megapixel prime-focus imager developed by a consortium including NOAO, FNAL, Brazilian National Observatory, and University of Illinois Urbana-Champaign. The focal plane uses CCDs produced by teams at Lawrence Berkeley National Laboratory and serviced via facilities like Cerro Tololo Inter-American Observatory. Survey strategies adopted tile patterns, exposure times, and cadence inspired by predecessors like Pan-STARRS and designed to meet requirements for signal-to-noise, image quality, and depth across fields overlapping legacy surveys such as the Sloan Digital Sky Survey and the Cosmos (survey). Calibration efforts drew on standard star networks including ties to HST CALSPEC and photometric systems traced to Landolt standards.

Data Management and Processing

DES data management was handled by pipelines at Fermilab and NCSA using software frameworks and databases developed in collaboration with groups from University of Illinois and University of Bonn. Processing steps included bias subtraction, flat-fielding, astrometric solutions referenced to GAIA DR1, coaddition, and catalog generation incorporating photometric redshift estimates trained on spectroscopic samples from VVDS, DEEP2, and SDSS. Quality assurance involved comparison to external datasets from WISE, 2MASS, and Pan-STARRS1. The collaboration adopted practices influenced by projects like LSST Science Collaborations and distributed data access protocols similar to those used by Sloan Digital Sky Survey.

Collaborators and Organizational Structure

Membership spanned more than 400 scientists across institutions such as Fermilab, Cerro Tololo Inter-American Observatory, University of Oxford, University of Pennsylvania, University of Edinburgh, University of Pennsylvania, University of Tokyo, University of Sao Paulo, and University of British Columbia. Leadership roles included a director, deputy directors, and conveners for working groups covering weak lensing, clustering, clusters, supernovae, calibration, and simulations. The collaboration interfaced with funding agencies like the U.S. Department of Energy, National Science Foundation (United States), CONICYT (Chile), and international partners including CONICET and CNPq.

Key Discoveries and Publications

DES produced high-impact results: cosmological constraints from combined probes refining omega_m and sigma_8 parameters, weak lensing mass maps revealing filamentary structure comparable to maps from Planck (spacecraft) and ACT (Atacama Cosmology Telescope), discovery and cataloging of galaxy clusters with follow-up from Chandra X-ray Observatory and XMM-Newton (satellite), and supernova cosmology samples extending redshift coverage relative to SNLS. Major publications appeared in journals alongside collaborative analyses with teams from SDSS-IV, Pan-STARRS, and KiDS (Kilo-Degree Survey), contributing to tensions discussed in contexts like the Hubble tension and S8 tension.

Outreach and Education Programs

Outreach initiatives connected to DES involved institutions such as Fermilab and NOIRLab, producing public data releases, educational materials for schools in regions around La Serena, and citizen science projects comparable to Galaxy Zoo. Training programs for graduate students and postdoctoral researchers included partnerships with National Optical-Infrared Astronomy Research Laboratory and summer schools organized with collaborators from Institute for Astronomy, University of Hawaii and ICRAR. Public engagement leveraged exhibits, lectures tied to the American Astronomical Society meetings, and multimedia content distributed through partner institutions including University of Chicago and Lawrence Berkeley National Laboratory.

Category:Astronomical collaborations