J/A+A/544/A73ivo://CDS.VizieR/J/A+A/544/A73doi:10.26093/cds/vizier.35440073CDSde Boer T.J.L.Tolstoy E.Hill V.Saha A.Olszewski E.W.Mateo M.,Starkenburg E.Battaglia G.Walker M.G.2012-10-23T15:18:04Z2012-07-31T08:08:50ZCDS support team

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

cds-question@unistra.frgalaxiesphotometryinfrared-photometryvisible-astronomybroad-band-photometryWe present deep photometry in the B,V and I filters from CTIO/MOSAIC for about 270.000 stars in the Fornax dwarf Spheroidal galaxy, out to a radius of r_ell_~0.8{deg}. By combining the accurately calibrated photometry with the spectroscopic metallicity distributions of individual Red Giant Branch stars we obtain the detailed star formation and chemical evolution history of Fornax. Fornax is dominated by intermediate age (1-10Gyr) stellar populations, but also includes ancient (10-14Gyr), and young (<1Gyr) stars. We show that Fornax displays a radial age gradient, with younger, more metal-rich populations dominating the central region. This confirms results from previous works. Within an elliptical radius of 0.8 degrees, or 1.9kpc from the centre, a total mass in stars of 4.3*10^7^M_{sun}_ was formed, from the earliest times until 250Myr ago. Using the detailed star formation history, age estimates are determined for individual stars on the upper RGB, for which spectroscopic abundances are available, giving an age-metallicity relation of the Fornax dSph from individual stars. This shows that the average metallicity of Fornax went up rapidly from [Fe/H]<-2.5dex to [Fe/H]=-1.5dex between 8-12Gyr ago, after which a more gradual enrichment resulted in a narrow, well-defined sequence which reaches [Fe/H]~-0.8dex, ~3Gyr ago. These ages also allow us to measure the build-up of chemical elements as a function of time, and thus determine detailed timescales for the evolution of individual chemical elements. A rapid decrease in [Mg/Fe] is seen for the stars with [Fe/H]>-1.5dex, with a clear trend in age.2012A&A...544A..73Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/544/A73CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/PASP/110/533 : BR photometry of Fornax bright stars (Stetson+ 1998)J/AJ/123/840 : VI photometry of variable stars in Fornax (Bersier+, 2002)J/AJ/127/840 : VRI photometry of Fornax red giants (Pont+, 2004)J/AJ/131/912 : BR photometry of Fornax dSph center (Olszewski+, 2006)J/AJ/131/2114 : Radial velocities in Fornax dSph (Walker+, 2006)J/A+A/459/423 : VI and [Fe/H] of Fornax dSph RGB stars (Battaglia+, 2006)J/A+A/467/1025 : JHK photometry of Fornax red giant branch (Gullieuszik+ 2007)J/ApJ/685/947 : SX Phe stars in Fornax. II. (Poretti+, 2008)J/ApJ/701/1323 : Variable stars in Fornax dSph. III. (Greco+, 2009)J/MNRAS/394/795 : AGB stars in Fornax dwarf spheroidal galaxy (Whitelock+ 2009)J/A+A/523/A17 : Individual stars in Fornax dSph center (Letarte+, 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/544/A73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/544/A73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/544/A73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/544/A73https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/544/A73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/544/A73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/544/A73/table1 (VBI photometry for all our targets in Fornax)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/544/A73/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/544/A73/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/544/A73/table1?GETtext/xml+votable180.050000true39.5831667-33.98209440.0055555555555555565/8992 6/35882-35883 35886 359722.263356695087955e-19 5.012217439694221e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/544/A73?format=asciiOpticalInfrareddefaultJ/A+A/544/A73/table1VBI photometry for all our targets in FornaxrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension J2000pos.eq.ra;meta.mainindexedDEJ2000Declination J2000pos.eq.dec;meta.mainindexedVmagV magnitudemagphot.mag;em.opt.Vfloate_Vmag? Error on V magnitudemagstat.error;phot.mag;em.opt.Vfloatnullableq_Vmag[0/3] Quality flag for V magnitude (1)meta.code.qualintBmag? B magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag? Error on B magnitudemagstat.error;phot.mag;em.opt.Bfloatnullableq_Bmag[0/3] Quality flag for B magnitude (1)meta.code.qualintImag? I magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag? Error on I magnitudemagstat.error;phot.mag;em.opt.Ifloatnullableq_Imag[0/3] Quality flag for I magnitude (1)meta.code.qualint