J/AJ/166/3ivo://CDS.VizieR/J/AJ/166/3doi:10.26093/cds/vizier.51660003CDSJohnson C.I.Calamida A.Kader J.A.Ferraro I.Pilachowski C.A.,Bono G.Mastrobuono-Battisti A.Rest A.Zenteno A.Zocchi A.2024-11-06T20:18:37Z2024-02-09T06:09:40ZCDS support team

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

cds-question@unistra.fropen-star-clustersinfrared-photometryvisible-astronomybroad-band-photometrygiant-starshorizontal-branch-starsWide-field and deep DECam multiband photometry, combined with HST data for the core of the Galactic globular cluster NGC2808, allowed us to study the distribution of various stellar subpopulations and stars in different evolutionary phases out to the cluster tidal radius. We used the Cugi=(u-g)-(g-i) index to identify three chemically distinct subpopulations along the red giant branch and compared their spatial distributions. The most light-element-enriched subpopulation (P3) is more centrally concentrated; however, it shows a more extended distribution in the external regions of the cluster compared to the primordial (P1) and intermediate (P2) composition populations. Furthermore, the P3 subpopulation centroid is off-center relative to those of the P1 and P2 groups. We also analyzed the spatial distribution of horizontal branch stars and found that the relative fraction of red horizontal branch stars increases for radial distances larger than ~1.5', while that of the blue and hotter stars decreases. These new observations, combined with literature spectroscopic measurements, suggest that the red horizontal branch stars are the progeny of all the stellar subpopulations in NGC 2808, i.e., primordial and light-element enhanced, while the blue stars are possibly the result of a combination of the "hot-flasher" and the "helium-enhanced" scenarios. A similar distribution of different red giant branch subpopulations and horizontal branch stars was also found for the most massive Galactic globular cluster, {omega} Cen, based on combined DECam and HST data, which suggests that the two may share a similar origin.2023AJ....166....3Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/166/3CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/AJ/109/218 : Catalogue of globular cluster profiles (Trager+ 1995)J/ApJ/562/368 : UV photometry in NGC 2808 (Brown+, 2001)J/ApJS/161/304 : Star clusters in Milky Way and satellites (McLaughlin+, 2005)J/ApJ/663/1021 : Log of {omega} Cen scientific images (Castellani+, 2007)J/AJ/133/1658 : ACS survey of galactic globular clusters (Sarajedini+, 2007)J/A+A/505/117 : Abundances redgiants in 15 globular clusters (Carretta+, 2009)J/A+A/517/A81 : 2 & 3d parameters of HB of globular clusters (Gratton+, 2010)J/A+A/534/A123 : Horizontal branch stars in NGC 2808 (Gratton+, 2011)J/A+A/526/A136 : Hot HB stars in {omega} Cen (Moehler+, 2011)J/A+A/528/A127 : Radial velocities in the globular NGC 2808 (Moni Bidin+, 2011)J/ApJ/754/L38 : Abundances & radial velocities of M13 giants (Johnson+, 2012)J/ApJ/810/148 : Red giant abundances in NGC 2808 (Carretta, 2015)J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)J/A+A/618/A15 : Parameters of EHB stars in {omega} Cen (Latour+, 2018)J/MNRAS/485/4906 : GC number density profiles using Gaia DR2 (de Boer+, 2019)J/MNRAS/485/4311 : Light element discontinuities in NGC 6402 (Johnson+, 2019)J/A+A/631/A14 : NGC 2808 stellar population spectra (Latour+, 2019)J/MNRAS/505/5978 : Gaia EDR3 view Galactic globular clusters (Vasiliev+, 2021)http://astroarchive.noirlab.edu/ : NOIRLab data archivehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/166/3https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/166/3http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/166/3https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/166/3https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/166/3http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/166/3GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/166/3/table2 (Log of NGC 2808 DECam observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/166/3/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/166/3/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/166/3/table2?GETtext/xml+votable180.050000true138.0010417-64.86297220.0055555555555555566/21850 25946 26266 27238 27289 37291 37294-37295 37633 37635-37636https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/166/3?format=asciiOpticalInfrareddefaultJ/AJ/166/3/table2Log of NGC 2808 DECam observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFileFile identifiermeta.id;meta.filecharObs[2014/2018] Observation yeartime.epochIDProposal identifiermeta.id;meta.maincharPIPrinciple Investigator nameobs.observercharFiltFilter usedinstr.setup;instr.filtercharTexp[10/600] Exposure timestime.duration;obs.exposureintRAJ2000[8/14] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainSeeing[0.76/2.22] Seeingarcsecinstr.obsty.seeingfloatAir[1.15/1.99] Airmassobs.airMassfloat