The Dark Energy Camera Plane Survey (DECaPS) is a multi-band imaging survey obtained with the Dark Energy Camera (DECam) to map the Galactic Plane. Browse these pages to learn more about DECaPS and to access the data. The DECaPS overview paper (Schlafly et al. 2017) describes the survey in detail, including its goals, survey strategy, reduction, and calibration. More information is also available on the DECaPS team website. The table below contain an overview of DECaPS properties.
|DECaPS Summary Table|
|Area covered||~1000 deg2|
|Depth (5σ, grizY)||23.7, 22.8, 22.2, 21.8, 21.0 mag|
|Number of objects||~2,000,000,000|
|Offsets to add to DECaPS mags to obtain AB (grizY)||0.020, 0.033, 0.024, 0.028, 0.011 mag|
The table below lists the tables available in the decaps_dr1 database. A few important notes about the object table are listed on the DECaPS Catalogs webpage, and copied below for reference:
A "good" detection in these catalogs means that the detection's central pixel had no "bad" flags set in the Community Pipeline data quality image, and that at least 85% of the source's flux (according to the model PSF and model location of the source) lands in a pixel with non-zero weight, according to the Community Pipeline inverse variance image.
All fluxes are in units of "3631 Jy," so that the AB magnitudes of the stars are given by -2.5*log10(flux)
The absolute calibration is based on the Tonry et al. (2012) absolute calibration of PS1. Subsequent analyses (Scolnic et al., 2014, 2015) of the PS1 survey found offsets relative to AB. To shift the DECaPS magnitudes to the Scolnic et al. (2015) absolute calibration, offsets of 0.020, 0.033, 0.024, 0.028, and 0.011 mag must be added to the DECaPS grizY magnitudes, respectively.
|DECaPS Database Tables|
|ccds||Brick CCD Table|
|depth||Brick Depth Table|
|imdb||Image Header Table|
|zps||Zero Points, Flat Fields & QA Table|
The DECaPS first data release took place in October 2017. It was published on the DECaPS team website, and described in an accompanying paper (Schlafly et al. 2017). The data release was also featured in a NOAO Currents article.
The DECaPS data are released in two stages at the Astro Data Lab. First, we release the object table, which corresponds to the band-merged catalogs loaded into a database table, as well as the survey tables (ccds, depth, imdb, zps). In the future, we will also release a measurement table consisting of the individual-image catalogs. The latter will be modified relative to the current version availavle on the DECaPS team website to include the obj_id allowing to join directly with the object table.