The Dark Energy Survey Data Release 1 (1801.03181v3)

Abstract: We describe the first public data release of the Dark Energy Survey, DES DR1, consisting of reduced single epoch images, coadded images, coadded source catalogs, and associated products and services assembled over the first three years of DES science operations. DES DR1 is based on optical/near-infrared imaging from 345 distinct nights (August 2013 to February 2016) by the Dark Energy Camera mounted on the 4-m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. We release data from the DES wide-area survey covering ~5,000 sq. deg. of the southern Galactic cap in five broad photometric bands, grizY. DES DR1 has a median delivered point-spread function of g = 1.12, r = 0.96, i = 0.88, z = 0.84, and Y = 0.90 arcsec FWHM, a photometric precision of < 1% in all bands, and an astrometric precision of 151 mas. The median coadded catalog depth for a 1.95" diameter aperture at S/N = 10 is g = 24.33, r = 24.08, i = 23.44, z = 22.69, and Y = 21.44 mag. DES DR1 includes nearly 400M distinct astronomical objects detected in ~10,000 coadd tiles of size 0.534 sq. deg. produced from ~39,000 individual exposures. Benchmark galaxy and stellar samples contain ~310M and ~ 80M objects, respectively, following a basic object quality selection. These data are accessible through a range of interfaces, including query web clients, image cutout servers, jupyter notebooks, and an interactive coadd image visualization tool. DES DR1 constitutes the largest photometric data set to date at the achieved depth and photometric precision.

• The paper introduces DES DR1, detailing the release of optical/near-IR imaging data from 345 nights covering nearly 5000 square degrees.
• It employs both single-epoch and multi-epoch coaddition techniques to achieve photometric precision below 1% and astrometric accuracy of about 151 mas.
• The paper underscores the release’s impact on dark energy studies by enabling precise measurements of cosmic acceleration through multiple observational methods.

An Overview of The Dark Energy Survey Data Release 1

The paper provides a comprehensive account of the first public data release of the Dark Energy Survey (DES), designated as DES DR1. This release includes data accumulated during the first three years of DES operations. The DES DR1 encompasses a vast amount of astronomical data derived from optical/near-infrared imaging, conducted using the Dark Energy Camera (DECam) mounted on the Blanco 4-m telescope at the Cerro Tololo Inter-American Observatory in Chile.

Scope and Methodology

DES aims to address fundamental questions regarding cosmic acceleration and the nature of dark energy. It utilizes four primary techniques: weak gravitational lensing, galaxy cluster counts, large-scale galaxy clustering, including baryon acoustic oscillations, and Type Ia supernovae distance measurements. To fulfill these scientific objectives, DES conducts a wide-area survey covering 5000 square degrees and a smaller supernova survey.

The DR1 release incorporates data from 345 nights between August 2013 and February 2016, achieving a remarkable photometric precision of less than 1% across all bands (grizY) and astrometric precision of approximately 151 mas when compared to Gaia. The data processing employed involves both single-epoch (Final Cut) and multi-epoch (coaddition) methodologies, optimizing for enhanced depth and precision of the photometric measurements.

Data Products

DES DR1 includes reduced single-epoch images, coadded images, and coadded source catalogs, covering a sky area amounting to nearly 5000 square degrees. Within this expanse, the survey delivered an impressive median point-spread function, reaching a coadded catalog depth of $g=24.33$, $r=24.08$, $i=23.44$, $z=22.69$, $Y=21.44$ mag for a signal-to-noise ratio of 10. Over 400 million distinct astronomical objects were cataloged, comprising a substantial galaxy sample and stellar sample, numbering 310 million and 80 million, respectively.

Implications and Future Outlook

The release of DES DR1 signifies a pivotal contribution to the scientific community, providing an extensive dataset that supports a multitude of astronomical and cosmological inquiries. The refined photometric and astrometric precision opens possibilities for enhanced understanding of dark energy and cosmic acceleration. Additionally, the availability of this data via public interfaces such as the DESaccess, LIneA Science Server, and NOAO Data Lab ensures broad accessibility for scientific exploitation.

The methodologies and techniques refined through DES have potential applications beyond dark energy studies, including the exploration of large scale structures, stellar populations, and other celestial phenomena. As DES completes its scheduled observations, future data releases are anticipated to build upon the foundation established by DR1, further enriching the astronomical community's capability to interrogate the cosmos.

In summary, DES DR1 serves as a vital resource for advancing both theoretical and applied astrophysics, promising to catalyze significant advancements in the field with its unprecedented depth and breadth of photometric data.