J/ApJ/797/15ivo://CDS.VizieR/J/ApJ/797/15doi:10.26093/cds/vizier.17970015CDSLarsen S.S.Brodie J.P.Grundahl F.Strader J.2015-11-05T18:32:06Z2015-09-23T08:25:14ZCDS support team

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

cds-question@unistra.frhst-photometryglobular-star-clustersWe use measurements of nitrogen abundances in red giants to search for multiple stellar populations in the four most metal-poor globular clusters (GCs) in the Fornax dwarf spheroidal galaxy (Fornax 1, 2, 3, and 5). New imaging in the F343N filter, obtained with the Wide Field Camera 3 on the Hubble Space Telescope, is combined with archival F555W and F814W observations to determine the strength of the NH band near 3370{AA}. After accounting for observational errors, the spread in the F343N-F555W colors of red giants in the Fornax GCs is similar to that in M15 and corresponds to an abundance range of {Delta}[N/Fe]~2dex, as observed also in several Galactic GCs. The spread in F555W-F814W is, instead, fully accounted for by observational errors. The stars with the reddest F343N-F555W colors (indicative of N-enhanced composition) have more centrally concentrated radial distributions in all four clusters, although the difference is not highly statistically significant within any individual cluster. From double-Gaussian fits to the color distributions, we find roughly equal numbers of "N-normal" and "N-enhanced" stars (formally ~40% N-normal stars in Fornax 1, 3, and 5 and ~60% in Fornax 2). We conclude that GC formation, in particular, regarding the processes responsible for the origin of multiple stellar populations, appears to have operated similarly in the Milky Way and in the Fornax dSph. Combined with the high ratio of metal-poor GCs to field stars in the Fornax dSph, this places an important constraint on scenarios for the origin of multiple stellar populations in GCs.2014ApJ...797...15Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/797/15CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)VII/151 : Structure Parameters of Galactic Globular Clusters (Webbink 1985)J/A+A/572/A82 : Abundances in outer parts of Fornax dSph (Hendricks+, 2014)J/A+A/562/A24 : Cool carbon stars in the halo and Fornax dSph (Mauron+, 2014)J/ApJ/772/82 : A catalog of globular cluster systems (Harris+, 2013)J/ApJ/763/40 : UBVI phot. of GCs in the Fornax galaxy cluster (Kim+, 2013)J/A+A/544/A73 : BVI photometry of Fornax dSph galaxy (de Boer+, 2012)J/A+A/534/A136 : Halo red giants from the SEGUE survey (Martell+, 2011)J/A+A/534/A9 : Synthetic spectra of galactic GCs (Sbordone+, 2011)J/ApJS/193/1 : UBVRIJHK color-temperature calibration (Worthey+, 2011)J/ApJ/705/1481 : Spectroscopy of stars in 6 GCs (Da Costa+, 2009)J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009)J/ApJ/701/1323 : Variable stars in Fornax dSph. III. (Greco+, 2009)J/ApJ/689/1031 : Heavy element abundances in giant stars (Yong+, 2008)J/A+A/486/437 : CN and CH line strengths in 8 Galactic GlCl (Kayser+, 2008)J/ApJ/681/197 : ACS Virgo Cluster Survey. XV (Peng+, 2008)J/A+A/459/423 : VI and [Fe/H] of Fornax dSph RGB stars (Battaglia+, 2006)J/MNRAS/345/747 : RR Lyrae in 4 Fornax globular clusters (Mackey+, 2003)J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)J/AJ/118/1671 : Fornax cluster 4 VI photometry (Buonanno+, 1999)J/A+AS/139/393 : Young Massive Star Clusters. II. (Larsen, 1999)J/A+A/317/54 : Fornax cluster 1 and 3 photometry (Jorgensen+ 1997)J/AJ/114/1471 : Fornax Globular 3 (Smith+ 1997)J/AJ/111/1596 : BV photometry in Fornax globulars (Smith+ 1996)J/A+AS/106/199 : B-band photometry in Fornax and Virgo (Caon+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/797/15https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/797/15http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/797/15https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/797/15https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/797/15http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/797/15GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/797/15/table2 (Photometry for Fornax 2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/797/15/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/797/15/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/797/15/table2?GETtext/xml+votable180.050000true39.68967028-34.806660830.005555555555555556Cone search capability for table J/ApJ/797/15/table3 (Photometry for Fornax 3)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/797/15/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/797/15/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/797/15/table3?GETtext/xml+votable180.050000true39.956255-34.258263610.005555555555555556Cone search capability for table J/ApJ/797/15/table4 (Photometry for Fornax 5)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/797/15/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/797/15/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/797/15/table4?GETtext/xml+votable180.050000true40.59295056-34.098539720.005555555555555556Cone search capability for table J/ApJ/797/15/table1 (Photometry for Fornax 1)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/797/15/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/797/15/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/797/15/table1?GETtext/xml+votable180.050000true39.26353139-34.183958890.0055555555555555566/35968 35969 359702.0401237512456292e-19 5.993397539078468e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/797/15?format=asciiOpticaldefaultJ/ApJ/797/15/table2Photometry for Fornax 2ID[5/57575] Identification number (1)meta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXpixX pixel coordinate in F555W imagepixpos.framefloatYpixY pixel coordinate in F555W imagepixpos.framefloatF555W[18.1/27.2] HST/WFPC2 F555W band magnitudemagphot.mag;em.opt.Vfloate_F555W[0.003/0.3] ALLFRAME error in F555Wmagmagstat.errorfloats_F555W[0.009/1.4] Weighted RMS deviation of individual F555Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF814W[17.7/27.9] HST/WFPC2 F814W band magnitudemagphot.mag;em.opt.Ifloate_F814W[0.004/0.3] ALLFRAME error in F814Wmagmagstat.errorfloats_F814W[0.008/1.6] Weighted RMS deviation of individual F814Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF343N[20.7/27.3] HST/WFC3 F343N band magnitudemagphot.mag;em.opt.Ufloate_F343N[0.009/0.4] ALLFRAME error in F343Nmagmagstat.errorfloats_F343N[0.008/2] Weighted RMS deviation of individual F343Nmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloat_RAPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.08'') (right ascension part)degpos.eq.ra;meta.main_DEPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.08'') (declination part)degpos.eq.dec;meta.mainJ/ApJ/797/15/table3Photometry for Fornax 3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[5/57575] Identification number (1)meta.id;meta.mainintXpixX pixel coordinate in F555W imagepixpos.framefloatYpixY pixel coordinate in F555W imagepixpos.framefloatF555W[18.1/27.2] HST/WFPC2 F555W band magnitudemagphot.mag;em.opt.Vfloate_F555W[0.003/0.3] ALLFRAME error in F555Wmagmagstat.errorfloats_F555W[0.009/1.4] Weighted RMS deviation of individual F555Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF814W[17.7/27.9] HST/WFPC2 F814W band magnitudemagphot.mag;em.opt.Ifloate_F814W[0.004/0.3] ALLFRAME error in F814Wmagmagstat.errorfloats_F814W[0.008/1.6] Weighted RMS deviation of individual F814Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF343N[20.7/27.3] HST/WFC3 F343N band magnitudemagphot.mag;em.opt.Ufloate_F343N[0.009/0.4] ALLFRAME error in F343Nmagmagstat.errorfloats_F343N[0.008/2] Weighted RMS deviation of individual F343Nmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloat_RAPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.06'') (right ascension part)degpos.eq.ra;meta.main_DEPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.06'') (declination part)degpos.eq.dec;meta.mainJ/ApJ/797/15/table4Photometry for Fornax 5F343N[20.7/27.3] HST/WFC3 F343N band magnitudemagphot.mag;em.opt.UfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[5/57575] Identification number (1)meta.id;meta.mainintXpixX pixel coordinate in F555W imagepixpos.framefloatYpixY pixel coordinate in F555W imagepixpos.framefloatF555W[18.1/27.2] HST/WFPC2 F555W band magnitudemagphot.mag;em.opt.Vfloate_F555W[0.003/0.3] ALLFRAME error in F555Wmagmagstat.errorfloats_F555W[0.009/1.4] Weighted RMS deviation of individual F555Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF814W[17.7/27.9] HST/WFPC2 F814W band magnitudemagphot.mag;em.opt.Ifloate_F814W[0.004/0.3] ALLFRAME error in F814Wmagmagstat.errorfloats_F814W[0.008/1.6] Weighted RMS deviation of individual F814Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloate_F343N[0.009/0.4] ALLFRAME error in F343Nmagmagstat.errorfloats_F343N[0.008/2] Weighted RMS deviation of individual F343Nmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloat_RAPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.06'') (right ascension part)degpos.eq.ra;meta.main_DEPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.06'') (declination part)degpos.eq.dec;meta.mainJ/ApJ/797/15/table1Photometry for Fornax 1ID[5/57575] Identification number (1)meta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXpixX pixel coordinate in F555W imagepixpos.framefloatYpixY pixel coordinate in F555W imagepixpos.framefloatF555W[18.1/27.2] HST/WFPC2 F555W band magnitudemagphot.mag;em.opt.Vfloate_F555W[0.003/0.3] ALLFRAME error in F555Wmagmagstat.errorfloats_F555W[0.009/1.4] Weighted RMS deviation of individual F555Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF814W[17.7/27.9] HST/WFPC2 F814W band magnitudemagphot.mag;em.opt.Ifloate_F814W[0.004/0.3] ALLFRAME error in F814Wmagmagstat.errorfloats_F814W[0.008/1.6] Weighted RMS deviation of individual F814Wmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloatF343N[20.7/27.3] HST/WFC3 F343N band magnitudemagphot.mag;em.opt.Ufloate_F343N[0.009/0.4] ALLFRAME error in F343Nmagmagstat.errorfloats_F343N[0.008/2] Weighted RMS deviation of individual F343Nmag measurementsmagstat.stdev;phys.atmol.wOscStrengthfloat_RAPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.06'') (right ascension part)degpos.eq.ra;meta.main_DEPosition computed from a comparison with de Boer et al. 2012, J/A+A/544/A73 ({sigma}=0.06'') (declination part)degpos.eq.dec;meta.main