The Dark Energy Survey (DES) is a 5000 square degree grizY survey of the Southern sky aimed at understanding the accelerating expansion rate of the Universe. DES is using four complementary methods to do this: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. DES uses the 3 square degree Dark Energy Camera (DECam), a 570 Megapixel CCD imaging camera installed at the prime focus of on the Blanco 4m telescope at the Cerro Tololo Interamerican Observatory in northern Chile. The survey is being performed over a period of five years (2013-2018), and is recording information from roughly 300 million distant galaxies and 100 million Milky Way stars. DES is also pursuing a time domain survey over a 30 square degree area aimed at discovery of thousands of supernova and other transients. The DES Survey page contains a full description of the survey.
- Supernovae. DES observes a 30 square degree area, distributed over several fields, with a cadence aimed at discovering thousands of supernovae for use for cosmology.
- Weak gravitational lensing. The DES Collaboration is using the galaxies discovered by DES to make three dimensional mass maps through weak lensing, for analysis of the growth of structure.
- Galaxy clusters. Galaxy clusters are another probe of the growth of structure. Cosmological results from weak lensing and cluster analysis from the Year 1 data are available here.
- Baryon Acoustic Oscillations. The galaxies discovered by DES provide a sample to measure the evolution of the length imprinted on the matter distribution at the time of last scattering after the Big Bang.
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|DES DR2 Summary|
|Area covered||~5000 deg2|
|Median catalog depth for 1.95 arcsec diameter aperture at S/N~10 in grizY||24.7, 24.4, 23.8, 23.1, 21.7 mag|
|Median PSF FWHM in grizY||1.11, 0.95, 0.88, 0.83, 0.90 arcsec|
|Median astrometric internal precision||~27 mas|
|Number of co-added image tiles / single-epoch images||10,169 / 76,217|
|Number of objects / galaxies / stellar sources||691,483,608 / 543 million / 145 million|
|DES DR2 Tables|
|main||Main photometry; summary table|
|coverage||Coverage table; fraction of the Healpix 4096 (Nest) pixel covered by a certain band (values between 0 and 1)|
|des_dr2.x1p5__main__gaia_dr2__gaia_source||Crossmatch of DES DR2 main table with Gaia DR2 gaia_source table; 1.5 arcsec matching radius, single-nearest match only|
|des_dr2.x1p5__main__nsc_dr2__object||Crossmatch of DES DR2 main table with NSC DR2 object table; 1.5 arcsec matching radius, single-nearest match only|
|des_dr2.x1p5__main__allwise__source||Crossmatch of DES DR2 main table with AllWISE source table; 1.5 arcsec matching radius, single-nearest match only|
|des_dr2.x1p5__main__unwise_dr1__object||Crossmatch of DES DR2 main table with unWISE DR1 object table; 1.5 arcsec matching radius, single-nearest match only|
|des_dr2.x1p5__main__sdss_dr16__specobj||Crossmatch of DES DR2 main table with SDSS DR16 specobj table; 1.5 arcsec matching radius, single-nearest match only|
|DES DR1 Summary|
|Area covered||5000 deg2|
|Depth (10σ, grizY)||24.45, 24.3, 23.5, 22.90, 21.70 mag|
|Seeing (grizY)||~1 arcsec|
|Number of Tiles||10338|
|Number of objects||399,263,026|
|DES DR1 Tables|
|hpix||HEALPIX tile table|
|main||Main object summary table|
|neighbors||Objects within 30 arcsec|
|tile_info||Tile information table|
|vhs_des||VISTA Hemisphere Survey crossmatch|
|band_g||Single-band SExtractor table|
|band_i||Single-band SExtractor table|
|band_r||Single-band SExtractor table|
|band_y||Single-band SExtractor table|
|band_z||Single-band SExtractor table|
|vac_sextractor||SExtractor summary table|
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