The Spitzer/IRAC Legacy over the GOODS Fields: Full-Depth 3.6, 4.5, 5.8
  and 8.0um Mosaics and Photometry for > 9000 Galaxies at z~3.5-10 from the
  GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS)
  We present the deepest Spitzer/IRAC $3.6$, $4.5$, $5.8$ and $8.0\mu$m
wide-area mosaics yet over the GOODS-N and GOODS-S fields as part of the GOODS
Re-ionization Era wide-Area Treasury from Spitzer (GREATS) project. We reduced
and mosaicked in a self-consistent way observations taken by the 11 different
Spitzer/IRAC programs over the two GOODS fields from 12 years of Spitzer
cryogenic and warm mission data. The cumulative depth in the $3.6\mu$m and
$4.5\mu$m bands amounts to $\sim 4260$ hr, $\sim 1220$ hr of which are new very
deep observations from the GREATS program itself. In the deepest area, the
full-depth mosaics reach $\gtrsim200$ hr over an area of $\sim100$ arcmin$^2$,
corresponding to a sensitivity of $\sim29$ AB magnitude at $3.6\mu$m ($1\sigma$
for point sources). Archival cryogenic $5.8\mu$m and $8.0\mu$m band data (a
cumulative 976 hr) are also included in the release. The mosaics are projected
onto the tangential plane of CANDELS/GOODS at a $0.3''$ pixel$^{-1}$ scale.
This paper describes the methodology enabling, and the characteristics of, the
public release of the mosaic science images, the corresponding coverage maps in
the four IRAC bands, and the empirical Point-Spread Functions (PSFs). These
PSFs enable mitigation of the source blending effects by taking into account
the complex position-dependent variation in the IRAC images. The GREATS data
products are in the Infrared Science Archive (IRSA). We also release the
deblended $3.6$-to-$8.0\mu$m photometry for $9192$ Lyman-Break galaxies at
$z\sim3.5-10$. GREATS will be the deepest mid-infrared imaging until JWST and,
as such, constitutes a major resource for characterizing early galaxy assembly.
