unWISE Coadds: The Five-year Data Set

Understand

We present full-sky coadded maps created by uniformly combining the first five years of Wide-field Infrared Survey Explorer (WISE) and NEOWISE imaging at 3.4 microns (W1) and 4.6 microns (W2).

• By incorporating both pre-hibernation WISE exposures from 2010-2011 and the first four years (2013-2017) of post-hibernation exposures from the NEOWISE-Reactivation mission, we are able to provide W1/W2 coadds that span a 15 times longer time baseline and are substantially deeper than the standard AllWISE data products.
• Our new five-year "full-depth" coadds are now the deepest ever all-sky maps at 3-5 microns, permitting detection of sources ~2 times (~0.7 mag) fainter than AllWISE at 5 sigma significance.
• We additionally present an updated set of "time-resolved" W1/W2 coadds, which separately stack each of ~10 sky passes at each inertial sky location, enabling motion and variability measurements for faint infrared sources over a long ~7.5 year time baseline.