J/ApJ/826/114ivo://CDS.VizieR/J/ApJ/826/114doi:10.26093/cds/vizier.18260114CDSToshikawa J.Kashikawa N.Overzier R.Malkan M.A.Furusawa H.,Ishikawa S.Onoue M.Ota K.Tanaka M.Niino Y.Uchiyama H.2019-02-04T10:31:44Z2018-03-12T12:38:02ZCDS support team

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

cds-question@unistra.frgalaxy-clustersredshiftedinfrared-photometryvisible-astronomybroad-band-photometryultraviolet-photometryline-intensitiesWe present the discovery of three protoclusters at z~3-4 with spectroscopic confirmation in the Canada-France-Hawaii Telescope Legacy Survey Deep Fields. In these fields, we investigate the large-scale projected sky distribution of z~3-6 Lyman-break galaxies and identify 21 protocluster candidates from regions that are overdense at more than 4{sigma} overdensity significance. Based on cosmological simulations, it is expected that more than 76% of these candidates will evolve into a galaxy cluster of at least a halo mass of 10^14^ M_{sun}_ at z=0. We perform follow-up spectroscopy for eight of the candidates using Subaru/FOCAS, Keck II/DEIMOS, and Gemini-N/GMOS. In total we target 462 dropout candidates and obtain 138 spectroscopic redshifts. We confirm three real protoclusters at z=3-4 with more than five members spectroscopically identified and find one to be an incidental overdense region by mere chance alignment. The other four candidate regions at z~5-6 require more spectroscopic follow-up in order to be conclusive. A z=3.67 protocluster, which has 11 spectroscopically confirmed members, shows a remarkable core-like structure composed of a central small region (<0.5 physical Mpc) and an outskirts region (~1.0 physical Mpc). The Ly{alpha} equivalent widths of members of the protocluster are significantly smaller than those of field galaxies at the same redshift, while there is no difference in the UV luminosity distributions. These results imply that some environmental effects start operating as early as at z~4 along with the growth of the protocluster structure. This study provides an important benchmark for our analysis of protoclusters in the upcoming Subaru/HSC imaging survey and its spectroscopic follow-up with the Subaru/PFS that will detect thousands of protoclusters up to z~6.2016ApJ...826..114Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/826/114CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/317 : The CFHTLS Survey (T0007 release) (Hudelot+ 2012)J/ApJ/648/7 : Ly{alpha} emitters at z=6.5 in Subaru Deep FieldJ/A+A/494/845 : Galaxy clusters in the CFHTLS (Grove+, 2009)J/A+A/509/A81 : Candidate clusters detected in six CFHTLS fields (Adami+, 2010)J/A+A/535/A65 : Galaxy clusters in the 4 CFHTLS Wide fields (Durret+, 2011)J/A+A/572/A41 : VUDS Dicovery of a high-redshift protocluster (Lemaux+, 2014)J/ApJ/799/60 : X-ray galaxy clusters in the CFHTLS fields (Mirkazemi+, 2015)J/ApJ/823/11 : Candidate Ly{alpha} emitting galaxies at z~3.8 (Dey+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/826/114https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/826/114http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/826/114https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/826/114https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/826/114http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/826/114GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/826/114/sources (Overview of the Protocluster Candidates in Table 4 (from Table 2 of the paper))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/826/114/sources?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/826/114/sources?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/826/114/sources?GETtext/xml+votable180.050000true36.826667-4.8496940.005555555555555556Cone search capability for table J/ApJ/826/114/table4 (Observed Properties of All Spectroscopically Confirmed Dropout Galaxies)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/826/114/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/826/114/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/826/114/table4?GETtext/xml+votable180.050000true36.82833333-4.835638890.0055555555555555566/11425 17686 17689 17692 48478 48479 48500 48501https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/826/114?format=asciiInfraredOpticalUVdefaultJ/ApJ/826/114/sourcesOverview of the Protocluster Candidates in Table 4 (from Table 2 of the paper)PopGalaxy populationsrc.classcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameProtocluster candidate name (DNADNN)meta.id;meta.maincharNgNumber of dropout galaxies in this protoclustermeta.numberintnullableRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainField[D1 D3 D4] CFHTLS fieldmeta.id;obs.fieldcharODensOverdensity significance (in {sigma} unit)stat.fit.goodnessfloatNgalNumber of dropout galaxies within 3 arcmin radius from its overdensity peakmeta.numberintSpec[Yes] Protocluster candidate observed by follow-up spectroscopy are marked as "Yes"meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/826/114/table4Observed Properties of All Spectroscopically Confirmed Dropout Galaxiese_magUncertainty in magmagstat.error;phot.magfloatzRedshiftsrc.redshiftfloatNameProtocluster candidate name (DNADNN)meta.id.parentcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/42] Dropout galaxy identifiermeta.id;meta.mainintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainmagApparent aperture magnitude of detection band (1)magphot.magfloatE_zUpper limit uncertainty in zstat.error;stat.maxfloate_zLower limit uncertainty in zstat.error;src.redshiftfloatUVMagUV absolute magnitude at 1300{AA} in the rest framemagphys.magAbsfloate_UVMagUncertainty in UVMagmagstat.error;phot.mag;em.UVfloatFLyaObserved Ly{alpha} line flux (in 10^-18^erg/s/cm^2^)1e-21W.m**-2phot.flux;em.UVfloate_FLyaUncertainty in FLya1e-21W.m**-2stat.errorfloatLLyaLy{alpha} luminosity (in 10^42^erg/s)1e+35Wphys.luminosityfloate_LLyaUncertainty in LLya1e+35Wstat.errorfloatEW0Rest-frame Ly{alpha} equivalent width ({AA})0.1nmspect.line.eqWidthfloate_EW0Uncertainty in EW00.1nmstat.errorfloatSwWeighted skewness ({AA})0.1nmmeta.notefloate_SwUncertainty in Sw0.1nmstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlchar