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Title: Full-Depth Coadds of the WISE and First-Year NEOWISE-Reactivation Images

The Near Earth Object Wide-field Infrared Survey Explorer (NEOWISE) Reactivation mission released data from its first full year of observations in 2015. This data set includes ~2.5 million exposures in each of W1 and W2, effectively doubling the amount of WISE imaging available at 3.4 μm and 4.6 μm relative to the AllWISE release. In this paper, we have created the first ever full-sky set of coadds combining all publicly available W1 and W2 exposures from both the AllWISE and NEOWISE-Reactivation (NEOWISER) mission phases. We employ an adaptation of the unWISE image coaddition framework, which preserves the native WISE angular resolution and is optimized for forced photometry. By incorporating two additional scans of the entire sky, we not only improve the W1/W2 depths, but also largely eliminate time-dependent artifacts such as off-axis scattered moonlight. We anticipate that our new coadds will have a broad range of applications, including target selection for upcoming spectroscopic cosmology surveys, identification of distant/massive galaxy clusters, and discovery of high-redshift quasars. In particular, our full-depth AllWISE+NEOWISER coadds will be an important input for the Dark Energy Spectroscopic Instrument selection of luminous red galaxy and quasar targets. Our full-depth W1/W2 coadds are already in use within themore » DECam Legacy Survey (DECaLS) and Mayall z-band Legacy Survey (MzLS) reduction pipelines. Finally, much more work still remains in order to fully leverage NEOWISER imaging for astrophysical applications beyond the solar system.« less
 [1] ; ORCiD logo [2] ; ORCiD logo [3]
  1. Berkeley Center for Cosmological Physics, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Univ. of Toronto, ON (Canada); Univ. of Waterloo, ON (Canada)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-05CH11231; AST-0950945
Accepted Manuscript
Journal Name:
Astronomical Journal (Online)
Additional Journal Information:
Journal Name: Astronomical Journal (Online); Journal Volume: 153; Journal Issue: 1; Journal ID: ISSN 1538-3881
IOP Publishing - AAAS
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); National Science Foundation (NSF)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; infrared; data analysis; surveys; image processing
OSTI Identifier: