J/ApJ/475/445ivo://CDS.VizieR/J/ApJ/475/445doi:10.26093/cds/vizier.14750445CDSMoustakas L.A.Davis M.Graham J.R.Silk J.Peterson B.A.Yoshii Y.2013-03-05T06:35:10Z1998-08-31T14:08:58ZCDS support team

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

cds-question@unistra.frgalaxiesphotometryinfrared-photometryWe combine deep K-band (W. M. Keck Telescope) with V- and I-band (New Technology Telescope) observations of two "blank" high Galactic latitude fields, surveying a total of ~2arcmin^2^. The K-band number-magnitude counts continue to rise above K~22mag, reaching surface densities of few x10^5^deg^-2^. The slope for the galaxy counts is approximately [dlog(N)/dmag].deg^-2^=0.23+/-0.02 over the range 18-23mag. While this slope is consistent with other recent deep K-band surveys, there is a definite scatter in the normalisations by about a factor of 2. In particular, our normalisation is ~2x greater than the galaxy counts reported by Djorgovski et al. in 1995 (1995ApJ...438L..13D). Optical near-infrared color-magnitude and color-color diagrams for all objects detected in the V+I+K image are plotted and discussed in the context of grids of Bruzual-Charlot isochrone synthesis galaxy evolutionary models. The colors of most of the observed galaxies are consistent with a population drawn from a broad redshift distribution. A few galaxies at K~19-20 are red in both colors (V-I>3; I-K>2, consistent with being early-type galaxies having undergone a burst of star formation at z>5 and viewed at z~1. At K>20, we find several (approximately eight) "red outlier" galaxies with I-K>4 and V-I<2.5, whose colors are difficult to mimic by a single evolving or nonevolving stellar population at any redshift unless they either have quite low metallicity or are highly reddened. We compare the data against the evolutionary tracks of second-burst ellipticals and against a grid of models that does not constrain galaxy ages to a particular formation redshift. The red outliers' surface density is several per square arcminute, which is so high that they are probably common objects of low luminosity L<L*. Whether these are low-metallicity, dusty dwarf galaxies, or old galaxies at high redshift, they are curious and merit spectroscopic follow-up.1997ApJ...475..445Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/475/445CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/475/445https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/475/445http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/475/445https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/475/445https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/475/445http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/475/445GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/475/445/table4 (Object catalog for field I)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/475/445/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/475/445/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/475/445/table4?GETtext/xml+votable180.050000true161.5142979-0.28321520.005555555555555556Cone search capability for table J/ApJ/475/445/table5 (Object catalog for field II)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/475/445/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/475/445/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/475/445/table5?GETtext/xml+votable180.050000true206.0967976-0.11725270.0055555555555555566/26022 270447.952274030004205e-20 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/475/445?format=asciiOpticalInfrareddefaultJ/ApJ/475/445/table4Object catalog for field IrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA1950Right ascension (1950)pos.eq.ra;meta.mainDE1950Declination (1950)pos.eq.dec;meta.mainxposX position (1)arcsecpos.cartesian.x;instr.platefloatyposY position (1)arcsecpos.cartesian.y;instr.platefloatVmagV magnitude (2)magphot.mag;em.opt.VfloatImagI magnitude (2)magphot.mag;em.opt.IfloatKmagK magnitudemagphot.mag;em.IR.Kfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexedJ/ApJ/475/445/table5Object catalog for field IIrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA1950Right ascension (1950)pos.eq.ra;meta.mainDE1950Declination (1950)pos.eq.dec;meta.mainxposX position (1)arcsecpos.cartesian.x;instr.platefloatyposY position (1)arcsecpos.cartesian.y;instr.platefloatVmagV magnitude (2)magphot.mag;em.opt.VfloatImagI magnitude (2)magphot.mag;em.opt.IfloatKmagK magnitudemagphot.mag;em.IR.Kfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexed