J/ApJS/221/23ivo://CDS.VizieR/J/ApJS/221/23doi:10.26093/cds/vizier.22210023CDSLabbe I.Oesch P.A.Illingworth G.D.van Dokkum P.G.Bouwens R.J.,Franx M.Carollo C.M.Trenti M.Holden B.Smit R.Gonzalez V.,Magee D.Stiavelli M.Stefanon M.2017-01-23T22:00:00Z2016-02-08T14:59:02ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsurveysinfrared-photometryThe IRAC ultradeep field and IRAC Legacy over GOODS programs are two ultradeep imaging surveys at 3.6 and 4.5{mu}m with the Spitzer Infrared Array Camera (IRAC). The primary aim is to directly detect the infrared light of reionization epoch galaxies at z>7 and to constrain their stellar populations. The observations cover the Hubble Ultra Deep Field (HUDF), including the two HUDF parallel fields, and the CANDELS/GOODS-South, and are combined with archival data from all previous deep programs into one ultradeep data set. The resulting imaging reaches unprecedented coverage in IRAC 3.6 and 4.5{mu}m ranging from >50hr over 150arcmin^2^, >100hr over 60sq arcmin^2^, to ~200hr over 5-10arcmin^2^. This paper presents the survey description, data reduction, and public release of reduced mosaics on the same astrometric system as the CANDELS/GOODS-South Wide Field Camera 3 (WFC3) data. To facilitate prior-based WFC3+IRAC photometry, we introduce a new method to create high signal-to-noise PSFs from the IRAC data and reconstruct the complex spatial variation due to survey geometry. The PSF maps are included in the release, as are registered maps of subsets of the data to enable reliability and variability studies. Simulations show that the noise in the ultradeep IRAC images decreases approximately as the square root of integration time over the range 20-200hr, well below the classical confusion limit, reaching 1{sigma} point-source sensitivities as faint as 15nJy (28.5 AB) at 3.6{mu}m and 18nJy (28.3 AB) at 4.5{mu}m. The value of such ultradeep IRAC data is illustrated by direct detections of z=7-8 galaxies as faint as H_AB_=28.2015ApJS..221...23Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/221/23CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/261 : GOODS initial results (Giavalisco+, 2004)J/ApJS/218/33 : Spitzer-CANDELS catalog within 5 deep fields (Ashby+, 2015)J/ApJ/803/34 : z~4-10 galaxies from HST legacy fields (Bouwens+, 2015)J/ApJS/214/24 : 3D-HST+CANDELS catalog (Skelton+, 2014)J/A+A/570/A11 : The Hawk-I UDS and GOODS Survey (HUGS) (Fontana+, 2014)J/MNRAS/432/2696 : Galaxy luminosity function at z = 7-9 (McLure+, 2013)J/ApJ/769/80 : Spitzer/IRAC observations of five deep fields (Ashby+, 2013)J/ApJ/756/164 : UV galaxies in CANDELS from z=8 to z=4 (Finkelstein+, 2012)J/ApJ/738/69 : SEDs of galaxies at 3.8<z<5 in GOODS (Shim+, 2011)J/ApJ/727/1 : IRAC/MUSYC SIMPLE survey (Damen+, 2011)J/ApJ/655/51 : HDFS IRAC observations of 2<z<3.5 galaxies (Wuyts+, 2007)J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)J/A+A/449/951 : GOODS-MUSIC sample: multicolour catalog (Grazian+, 2006)J/AJ/125/1107 : Ultra-deep near-IR observation in HDF-S (Labbe+, 2003)J/ApJ/513/34 : HDF photometric redshifts catalog (Fernandez-Soto+, 1999)http://www.strw.leidenuniv.nl/iudf/ : IRAC Ultradeep Field (IUDF) home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/221/23https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/221/23http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/221/23https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/221/23https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/221/23http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/221/23GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJS/221/23/table2Summary of individual AORsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPID[194/80217] Program Identifiermeta.id;obsintAORSpitzer/IRAC AOR keymeta.id;obsintMJD[53043.5/56779.7] Modified Julian Day in UTC at start of observationtime.epochdoubleArea[21.4/328.5] Total area (1)arcmin**2phys.angSizefloatExp[0.1/10.3] Mean exposure time in hour over Areahtime.expofloat