J/ApJ/800/18ivo://CDS.VizieR/J/ApJ/800/18doi:10.26093/cds/vizier.18000018CDSAtek H.Richard J.Kneib J.-P.Jauzac M.Schaerer D.Clement B.,Limousin M.Jullo E.Natarajan P.Egami E.Ebeling H.2017-12-22T05:33:30Z2015-07-29T09:10:05ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-sourceshst-photometryredshiftedgalaxy-clustersgravitational-lensingExploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant universe far beyond the limits of blank field surveys. Using the complete Hubble Space Telescope observations of the first HFF cluster A2744, we report the detection of 50 galaxy candidates at z~7 and eight candidates at z~8 in a total survey area of 0.96arcmin^2^ in the source plane. Three of these galaxies are multiply imaged by the lensing cluster. Using an updated model of the mass distribution in the cluster we were able to calculate the magnification factor and the effective survey volume for each galaxy in order to compute the ultraviolet galaxy luminosity function (LF) at both redshifts 7 and 8. Our new measurements reliably extend the z~7 UV LF down to an absolute magnitude of M_UV_~-15.5. We find a characteristic magnitude of M_UV_^*^=-20.90_-0.73_^+0.90^mag and a faint-end slope {alpha}=-2.01_-0.28_^+0.20^, close to previous determinations in blank fields. We show here for the first time that this slope remains steep down to very faint luminosities of 0.01L^*^. Although prone to large uncertainties, our results at z~8 also seem to confirm a steep faint-end slope below 0.1L^*^. The HFF program is therefore providing an extremely efficient way to study the faintest galaxy populations at z>7 that would otherwise be inaccessible with current instrumentation. The full sample of six galaxy clusters will provide even better constraints on the buildup of galaxies at early epochs and their contribution to cosmic reionization.2015ApJ...800...18Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/800/18CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/A+A/578/A105 : EELGs out to z~1 in zCOSMOS (Amorin+, 2015)J/MNRAS/443/1549 : MACSJ0416.1-2403 strong-lensing analysis (Jauzac+, 2014)J/MNRAS/440/2810 : Galaxy luminosity function at z =~ 7 (Bowler+, 2014)J/ApJ/765/47 : Lyman-break galaxies and LAEs at z~3 (Nestor+, 2013)J/ApJ/762/L30 : CLASH: MCS J0416.1-2403 strong lensing analysis (Zitrin+, 2013)J/ApJ/738/69 : SEDs of galaxies at 3.8<z<5 in GOODS (Shim+, 2011)J/ApJ/728/27 : Chandra and AAOmega observations of Abell 2744 (Owers+, 2011)J/A+A/500/947 : Spectroscopy and photometry in A2744 and A2537 (Braglia+, 2009)J/ApJ/668/643 : Multiply imaged gravitational lens systems (Limousin+, 2007)J/ApJ/653/53 : z~6 galaxies UV luminosity function (Bouwens+, 2006)J/ApJ/627/32 : Gravitationally lensed arcs in HST WFPC2 archive (Sand+, 2005)J/AJ/120/2747 : HDF-South WFPC2 observations (Casertano+, 2000)http://www.stsci.edu/hst/campaigns/frontier-fields/FF-Data : Frontier Fieldshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/800/18https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/800/18http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/800/18https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/800/18https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/800/18http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/800/18GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/800/18/table3 (Photometric and color measurements for the z~6-7 dropouts)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/800/18/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/800/18/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/800/18/table3?GETtext/xml+votable180.050000true3.59380639-30.415443890.005555555555555556Cone search capability for table J/ApJ/800/18/table4 (Photometric and color measurements for the z~8 dropouts)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/800/18/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/800/18/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/800/18/table4?GETtext/xml+votable180.050000true3.59216194-30.409916110.0055555555555555566/164861.2299896717679617e-19 1.7721910056019106e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/800/18?format=asciiInfraredOpticaldefaultJ/ApJ/800/18/table3Photometric and color measurements for the z~6-7 dropoutsl_I-YLimit flag on I-Ymeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[ARK2015][260/6670] Target numbermeta.id;meta.mainintRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainI-Y[0.8/3.6] HST I_814_-Y_105_ color indexmagphot.color;em.IR;em.IRfloate_I-Y[0.05/0.7]? I-Y uncertaintymagstat.errorfloatnullableY-J[-0.5/0.8] HST/WFC3 Y_105_-J_125_ color indexmagphot.color;em.IR;em.IRfloate_Y-J[0.01/0.6] Y-J uncertaintymagstat.errorfloatJmag[24/29.3] HST/WFC3 F125W (J_125_) AB magnitudemagphot.mag;em.IR.Jfloate_Jmag[0.01/0.5] Jmag uncertaintymagstat.error;phot.mag;em.IR.JfloatMag[1.7/30] Magnification (flux amplification factor)stat.fit.paramfloatz[5.4/7.4] Photometric redshiftsrc.redshiftfloatb_z[3/7] 68% lower limit on zsrc.redshift;stat.minfloatB_z[5/8] 68% upper limit on zsrc.redshift;stat.maxfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/800/18/table4Photometric and color measurements for the z~8 dropouts[ARK2015][1060/6593] Target numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainY-J[0.5/1.5] HST/WFC3 Y_105_-J_125_ color indexmagphot.color;em.IR;em.IRfloate_Y-J[0.1/0.5] Y-J uncertaintymagstat.errorfloatJ-H[-0.4/0.3] HST/WFC3 J_125_-H_140_ color indexmagphot.color;em.IR;em.IRfloate_J-H[0.08/0.4] J-H uncertaintymagstat.error;phot.color;em.IR.JfloatHmag[25/29] HST/WFC3 F140W (H_140_) AB magnitudemagphot.mag;em.IR.Hfloate_Hmag[0.05/0.3] Hmag uncertaintymagstat.error;phot.mag;em.IR.HfloatMag[1.8/16.5] Magnification (flux amplification factor)stat.fit.paramfloatz[7.3/8] Photometric redshiftsrc.redshiftfloatb_z[6/8] 68% lower limit on zsrc.redshift;stat.minfloatB_z[7/9] 68% upper limit on zsrc.redshift;stat.maxfloatSimbadSimbad column added by the CDSmeta.ref.urlchar