J/ApJ/765/71ivo://CDS.VizieR/J/ApJ/765/71doi:10.26093/cds/vizier.17650071CDSContreras Ramos R.Clementini G.Federici L.Fiorentino G.Cacciari C.,Catelan M.Smith H.A.Fusi Pecci F.Marconi M.Pritzl B.J.,Kinemuchi K.2018-01-30T07:18:08Z2014-11-26T08:05:12ZCDS support team

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

cds-question@unistra.frhst-photometryglobular-star-clustersvariable-starsWe present the first evidence that Oosterhoff type II globular clusters exist in the Andromeda galaxy (M31). On the basis of time-series photometry of the moderately metal-poor ([Fe/H]~-1.6dex) M31 globular cluster G11, obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope, we detected and derived periods for 14 RR Lyrae stars, of which five are found to lie inside the cluster tidal radius. They include three fundamental-mode (RRab) and two first-overtone (RRc) pulsators, with average periods <P_ab_>=0.70 days, and <P_c_>=0.40 days, respectively. These mean periods and the position of the cluster variable stars in the period-amplitude and period-metallicity diagrams all suggest that G11 is likely to be an Oosterhoff type II globular cluster. This appears to be in agreement with the general behavior of Milky Way globular clusters with similar metallicity and horizontal branch morphology.2013ApJ...765...71Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/765/71CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/AJ/148/4 : JHK photometry of 913 globular clusters in M31 (Wang+, 2014)J/ApJ/745/156 : M31 Cepheids with HST/WFC3 (Riess+, 2012)J/A+A/544/A155 : HST photometry of M31 globular clusters (Federici+, 2012)J/A+A/539/A138 : RR Lyr variable stars in M32 (Fiorentino+, 2012)J/MNRAS/425/1459 : RR Lyrae in M32 (Sarajedini+, 2012)J/AJ/141/171 : RRL stars in six ultra-deep fields of M31 (Jeffery+, 2011)J/MNRAS/402/803 : M31 globular cluster system (Peacock+, 2010)J/ApJ/725/200 : An updated cat. of M31 globular-like clusters (Fan+, 2010)J/ApJ/708/817 : RR Lyrae variables in M32 and M31 (Fiorentino+, 2010)J/A+A/508/1285 : Metallicities of M31 globular clusters (Galleti+, 2009)J/AJ/138/184 : RRL variables in 2 M31 spheroid fields (Sarajedini+, 2009)J/A+A/471/127 : New globular clusters in M31 (Galleti+, 2007)J/PASP/119/7 : HST WFPC2 star clusters in M31 (Krienke+, 2007)J/AJ/129/2232 : Variable stars in And I and And III (Pritzl+, 2005)J/AJ/129/267 : RR Lyrae variables in NGC 5272 (Cacciari+, 2005)J/A+A/416/917 : Revised Bologna Cat. of M31 GCs (Galleti+, 2004)J/AJ/127/2738 : ACS VI photometry of M31 halo RR Lyrea (Brown+, 2004)J/AJ/127/318 : BV photometry of Andromeda II variables (Pritzl+, 2004)J/AJ/124/1464 : Variable stars in Andromeda VI (Pritzl+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/765/71https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/765/71http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/765/71https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/765/71https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/765/71http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/765/71GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap2.0401237512456292e-19 3.9057996558789745e-19OpticaldefaultJ/ApJ/765/71/table3Identification and properties of the RRL stars identified in the FOV of the G11 observationsLCLight curvemeta.ref.urlcharCamCamera of the WFPC2 where the star is locatedmeta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_ID[bw] Location of star (1)meta.notecharIDStar identifiermeta.id;meta.maincharprimaryf_ID[abc, ] Flag(s) on star (2)meta.codecharXpos[84/763] Star's coordinate along X axis (3)pixmeta.idfloatYpos[97/709] Star's coordinate along Y axis (3)pixmeta.idfloatDist[2.7/99] Estimated distance from the cluster centerarcsecpos.angDistancefloatTypeRR Lyrae type (RRab or RRc)meta.notecharPer[0.3/0.8] Perioddtime.perioddoubleNpNumber of photometric measures (table 4)meta.numberintnullableEpochHeliocentric Julian date of maximum light; JD-2450000dtime.epochdouble<F606W>Intensity-averaged mean HST F606W magnitudemagphot.mag;em.opt.Rfloatu_<F606W><F606W> uncertainty flagmeta.code.errorchar<F814W>[24.4/25.1] Intensity-averaged mean HST F814W magnitudemagphot.mag;em.opt.Ifloatl_F606amp[>= ] Limit flag on F606ampsrc.var.amplitudecharF606ampF606W amplitude (A_F606W_)magsrc.var.amplitudefloatF814amp[0.2/0.9] F814W amplitude (A_F814W_)magsrc.var.amplitudefloat<Vmag>Intensity-averaged mean V-band magnitudemagphot.mag;em.opt.Vfloatu_<Vmag><Vmag> uncertainty flagmeta.code.error;pos.cartesian.ychar<Imag>[24.4/25.1] Intensity-averaged mean I-band magnitudemagphot.mag;em.opt.Ifloatl_Vamp[>= ] Limit flag on Vampsrc.var.amplitudecharVampV-band amplitude (A_V_)magsrc.var.amplitudefloatIamp[0.2/0.9] I-band amplitude (A_I_)magsrc.var.amplitudefloatJ/ApJ/765/71/table4F606W, F814W photometry for the RRL stars detected in this FOV of the G11 observationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identifiermeta.id;meta.maincharTypeRR Lyrae type (RRab or RRc)meta.notecharFiltHST/WFPC2 filter (F555W, F606W or F814W)meta.notecharHJDHeliocentric Julian Datedtime.epochdoublemag[23.9/26] Observed magnitude in Filtmagphot.magfloat