The Dark Energy Survey Data Release 2
Authors: Abbott T. M. C. , Adamów M. , Aguena M. , Allam S. , Amon A. , Annis J. , Avila S. , Bacon D. , Banerji M. , Bechtol K. , Becker M. R. , Bernstein G. M. , Bertin E. , Bhargava S. , Bridle S. L. , Brooks D. , Burke D. L. , Carnero Rosell A. , Carrasco Kind M. , Carretero J. , Castander F. J. , Cawthon R. , Chang C. , Choi A. , Conselice C. , Costanzi M. , Crocce M. , da Costa L. N. , Davis T. M. , De Vicente J. , DeRose J. , Desai S. , Diehl H. T. , Dietrich J. P. , Drlica-Wagner A. , Eckert K. , Elvin-Poole J. , Everett S. , Evrard A. E. , Ferrero I. , Ferté A. , Flaugher B. , Fosalba P. , Friedel D. , Frieman J. , García-Bellido J. , Gaztanaga E. , Gelman L. , Gerdes D. W. , Giannantonio T. , Gill M. S. S. , Gruen D. , Gruendl R. A. , Gschwend J. , Gutierrez G. , Hartley W. G. , Hinton S. R. , Hollowood D. L. , Honscheid K. , Huterer D. , James D. J. , Jeltema T. , Johnson M. D. , Kent S. , Kron R. , Kuehn K. , Kuropatkin N. , Lahav O. , Li T. S. , Lidman C. , Lin H. , MacCrann N. , Maia M. A. G. , Manning T. A. , Maloney J. D. , March M. , Marshall J. L. , Martini P. , Melchior P. , Menanteau F. , Miquel R. , Morgan R. , Myles J. , Neilsen E. , Ogando R. L. C. , Palmese A. , Paz-Chinchón F. , Petravick D. , Pieres A. , Plazas A. A. , Pond C. , Rodriguez-Monroy M. , Romer A. K. , Roodman A. , Rykoff E. S. , Sako M. , Sanchez E. , Santiago B. , Scarpine V. , Serrano S. , Sevilla-Noarbe I. , Smith J. Allyn , Smith M. , Soares-Santos M. , Suchyta E. , Swanson M. E. C. , Tarle G. , Thomas D. , To C. , Tremblay P. E. , Troxel M. A. , Tucker D. L. , Turner D. J. , Varga T. N. , Walker A. R. , Wechsler R. H. , Weller J. , Wester W. , Wilkinson R. D. , Yanny B. , Zhang Y. , Nikutta R. , Fitzpatrick M. , Jacques A. , Scott A. , Olsen K. , Huang L. , Herrera D. , Juneau S. , Nidever D. , Weaver B. A. , Adean C. , Correia V. , de Freitas M. , Freitas F. N. , Singulani C. , Vila-Verde G. ,   (Linea Science Server)
Published: July 2021

Abstract
We present the second public data release of the Dark Energy Survey, DES DR2, based on optical/near-infrared imaging by the Dark Energy Camera mounted on the 4 m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. DES DR2 consists of reduced single-epoch and coadded images, a source catalog derived from coadded images, and associated data products assembled from 6 yr of DES science operations. This release includes data from the DES wide-area survey covering ∼5000 deg2 of the southern Galactic cap in five broad photometric bands, grizY. DES DR2 has a median delivered point-spread function FWHM of g = 1.11″, r = 0.95″, i = 0.88″, z = 0.83″, and Y = 0.″90, photometric uniformity with a standard deviation of < 3 mmag with respect to Gaia DR2 G band, a photometric accuracy of ∼11 mmag, and a median internal astrometric precision of ∼27 mas. The median coadded catalog depth for a 1.″95 diameter aperture at signal-to-noise ratio = 10 is g = 24.7, r = 24.4, i = 23.8, z = 23.1, and Y = 21.7 mag. DES DR2 includes ∼691 million distinct astronomical objects detected in 10,169 coadded image tiles of size 0.534 deg2 produced from 76,217 single-epoch images. After a basic quality selection, benchmark galaxy and stellar samples contain 543 million and 145 million objects, respectively. These data are accessible through several interfaces, including interactive image visualization tools, web-based query clients, image cutout servers, and Jupyter notebooks. DES DR2 constitutes the largest photometric data set to date at the achieved depth and photometric precision.