J/ApJ/718/530ivo://CDS.VizieR/J/ApJ/718/530doi:10.26093/cds/vizier.17180530CDSSand D.J.Seth A.Olszewski E.W.Willman B.Zaritsky D.,Kallivayalil N.2012-07-27T09:06:14Z2012-07-27T09:05:34ZCDS support team

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

cds-question@unistra.frvisible-astronomysloan-photometrygalaxiesextinctionWe present MMT/Megacam imaging of the Leo IV dwarf galaxy in order to investigate its structure and star formation history, and to search for signs of association with the recently discovered Leo V satellite. Based on parameterized fits, we find that Leo IV is round, with {epsilon}<0.23 (at the 68% confidence limit) and a half-light radius of r_h_~130pc. Additionally, we perform a thorough search for extended structures in the plane of the sky and along the line of sight. We derive our surface brightness detection limit by implanting fake structures into our catalog with stellar populations identical to that of Leo IV. We show that we are sensitive to stream-like structures with surface brightness {mu}_r_<~29.6mag/arcsec^2^, and at this limit we find no stellar bridge between Leo IV (out to a radius of ~0.5kpc) and the recently discovered, nearby satellite Leo V. Using the color-magnitude fitting package StarFISH, we determine that Leo IV is consistent with a single age (~14Gyr), single metallicity ([Fe/H]~-2.3) stellar population, although we cannot rule out a significant spread in these values. We derive a luminosity of M_V_=-5.5+/-0.3. Studying both the spatial distribution and frequency of Leo IV's "blue plume" stars reveals evidence for a young (~2Gyr) stellar population which makes up ~2% of its stellar mass.2010ApJ...718..530Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/718/530CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/ApJ/710/1664 : BV photometry in Leo IV and Leo V dSphs (de Jong+, 2010)J/ApJS/191/352 : Abundances in stars of Milky Way dwarf satellites (Kirby+,https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/718/530https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/718/530http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/718/530https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/718/530https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/718/530http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/718/530GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/718/530/table1 (Leo IV photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/718/530/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/718/530/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/718/530/table1?GETtext/xml+votable180.050000true173.23115-0.546350.0055555555555555566/26980 26981https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/718/530?format=asciiOpticaldefaultJ/ApJ/718/530/table1Leo IV photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[SSO2010][0/25281] Star index numbermeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainindexedDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainindexedgmagThe g band magnitude; uncorrected for extinctionmagphot.mag;em.opt.Bfloate_gmagUncertainty in gmagmagstat.error;phot.mag;em.opt.BfloatAgGalactic extinction value in g bandmagphys.absorption.galfloatrmagThe r band magnitude; uncorrected for extinctionmagphot.mag;em.opt.Rfloate_rmagUncertainty in rmagmagstat.error;phot.mag;em.opt.RfloatArGalactic extinction value in r bandmagphys.absorption.galfloatRefPhotometry source; SDSS or MMTmeta.id;obscharDR7Display the SDSS-DR7 data (Cat. II/294)meta.ref.urlcharSloanDisplay the online SDSS data for this objectmeta.ref.urlchar