Overview
We make available full-depth mosaics, together with deblended photometry for ~9000 sources, in the Spitzer/IRAC 3.6um, 4.5um, 5.8um and 8.0um bands 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 essentially all observations taken by the 11 different Spitzer/IRAC programs that targeted the two fields across 12 years of Spitzer operations, which include both cryogenic and warm mission data. The cumulative exposure time in the 3.6um and 4.5um bands amounts to ∼4260hr, ∼1220hr of which are new observations from the GREATS program itself. We also make available empirical Point-Spread Functions that take into account the complex spatial variation of the survey geometry, essential to mitigate the source blending effects. These data represent the deepest mid-infrared imaging until the launch of JWST.
Full details on how these mosaics were created are presented in Stefanon et al. (2021b).
Mosaics layout
The corresponding full-depth mosaics provide a coverage of 200hr over an area of ∼ 100arcmin2, reaching approximately ∼ 29AB magnitude at 3.6um (1 sigma for point sources). Cumulative integration times in the 5.8um and 8.0um bands are ∼3−5 times shorter than in the 3.6um and 4.5um bands. The mosaics have the same tangential plane of CANDELS/GOODS, with a 0.3"/pixel scale.
The images below show the layouts of science (top rows) and exposure time maps (bottom rows) of the IRAC mosaics in the two GOODS fields. The orange contour corresponds to the HST/WFC3 NIR coverage from CANDELS/3D-HST.
[Jump to download section]
GOODS-N
GOODS-S
Download
The tables below provide links to download the science mosaics, exposure time maps, Point-Spread Function (PSF) maps, and photometric catalogs for 9192 Lyman-break galaxies at z~3.5-10 from Bouwens et al. (2015). A README file is also available here.
Science frames are calibrated to MJy/sr (AB zeropoint=23.086 mag), exposure time maps have units of seconds, while flux densities in the catalogs are in units of nJy. The mosaics have the same tangential plane of CANDELS/GOODS mosaics, with a 0.3"/pixel scale.
We also provide simple scripts in IDL and Python to reconstruct the PSF at any specific position across the mosaics.
You can download all data products as a single zip file (1.14 GB) from here (you will be redirected to a Surfdrive page).
Please cite Stefanon et al., ApJS (2021b) if you make use of any of these data in your publications.
| IRAC photometry for z~3.5-10 LBGs |
|---|
| GREATS_GOODS-N_LBG_v1.0.cat |
| GREATS_GOODS-S_all_LBG_v1.0.cat |
The GREATS Team
The GREATS Team is composed by Ivo Labbé (PI), Mauro Stefanon Pascal Oesch, Stephane de Barros, Valentino Gonzalez, Rychard Bouwens, Marijn Franx, Brad Holden, Garth Illingworth, Dan Magee, Renske Smit and Pieter van Dokkum.