SMASH - Survey of the MAgellanic Stellar History
  The Large and Small Magellanic Clouds (LMC and SMC) are unique local
laboratories for studying the formation and evolution of small galaxies in
exquisite detail. The Survey of the MAgellanic Stellar History (SMASH) is an
NOAO community DECam survey of the Clouds mapping 480 square degrees
(distributed over ~2400 square degrees at ~20% filling factor) to ~24th mag in
ugriz with the goal of identifying broadly distributed, low surface brightness
stellar populations associated with the stellar halos and tidal debris of the
Clouds. SMASH will also derive spatially-resolved star formation histories
covering all ages out to large radii from the MCs that will further complement
our understanding of their formation. Here, we present a summary of the survey,
its data reduction, and a description of the first public Data Release (DR1).
The SMASH DECam data have been reduced with a combination of the NOAO Community
Pipeline, PHOTRED, an automated PSF photometry pipeline based mainly on the
DAOPHOT suite, and custom calibration software. The attained astrometric
precision is ~15 mas and the accuracy is ~2 mas with respect to the Gaia DR1
astrometric reference frame. The photometric precision is ~0.5-0.7% in griz and
~1% in u with a calibration accuracy of ~1.3% in all bands. The median 5 sigma
point source depths in ugriz bands are 23.9, 24.8, 24.5, 24.2, 23.5 mag. The
SMASH data already have been used to discover the Hydra II Milky Way satellite,
the SMASH 1 old globular cluster likely associated with the LMC, and very
extended stellar populations around the LMC out to R~18.4 kpc. SMASH DR1
contains measurements of ~100 million objects distributed in 61 fields. A
prototype version of the NOAO Data Lab provides data access, including a data
discovery tool, SMASH database access, an image cutout service, and a Jupyter
notebook server with example notebooks for exploratory analysis.
