J/A+A/624/A25ivo://CDS.VizieR/J/A+A/624/A25doi:10.26093/cds/vizier.36240025CDSLarsen S.S.Baumgardt H.Bastian NHernandez S.Brodie J.P.2019-04-08T14:37:16Z2019-04-02T08:44:19ZCDS support team

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

cds-question@unistra.frglobular-star-clustershst-photometryinfrared-photometryvisible-astronomyWide-band photometrymetallicityWe present new deep imaging of the central regions of the remote globular cluster NGC 2419, obtained with the F343N and F336W filters of the Wide Field Camera 3 on board the Hubble Space Telescope. The new data are combined with archival imaging to constrain nitrogen and helium abundance variations within the cluster. We find a clearly bimodal distribution of the nitrogen-sensitive F336W-F343N colours of red giants, from which we estimate that about 55% of the giants belong to a population with about normal (field-like) nitrogen abundances (P1), while the remaining 45% belong to a nitrogen-rich population (P2). On average, the P2 stars are more He-rich than the P1 stars, with an estimated mean difference of {Delta}Y~=0.05, but the P2 stars exhibit a significant spread in He content and some may reach {Delta}Y~=0.13. A smaller He spread may also be present for the P1 stars. Additionally, stars with spectroscopically determined low Mg abundances ([Mg/Fe]<0) are generally associated with P2. We find the P2 stars to be slightly more centrally concentrated in NGC 2419 with a projected half-number radius of about 10% less than for the P1 stars, but the difference is not highly significant (p~=0.05). Using published radial velocities, we find evidence of rotation for the P1 stars, whereas the results are inconclusive for the P2 stars, which are consistent with no rotation as well as the same average rotation found for the P1 stars. Because of the long relaxation time scale of NGC 2419, the radial trends and kinematic properties of the populations are expected to be relatively unaffected by dynamical evolution. Hence, they provide constraints on formation scenarios for multiple populations, which must account not only for the presence of He spreads within sub-populations identified via CNO variations, but also for the relatively modest differences in the spatial distributions and kinematics of the populations.2019A&A...624A..25Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/624/A25CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/136/2259 : HST photometry of stars in NGC 2419 (Sandquist+, 2008)J/A+A/581/A72 : ubvy photometry of NGC2419 (Frank+, 2015)J/MNRAS/431/1995 : Deep uVI photometry of NGC2419 (Beccari+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/624/A25https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/624/A25http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/624/A25https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/624/A25https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/624/A25http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/624/A25GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/624/A25/tablea1 (Photometry for NGC 2419)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/624/A25/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/624/A25/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/624/A25/tablea1?GETtext/xml+votable180.050000true114.56110664538.8653315110.0055555555555555566/63892.0401237512456292e-19 4.2441532724171825e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/624/A25?format=asciiOpticalInfrareddefaultJ/A+A/624/A25/tablea1Photometry for NGC 2419mF606WF606W STMAG magnitudemagphot.mag;em.opt.RfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/79078] Running IDmeta.id;meta.mainintXposCCD X coordinatepixpos.cartesian.x;instr.detdoubleYposCCD Y coordinatepixpos.cartesian.y;instr.detdoubleRAJ2000Right Ascension (J2000.0)degpos.eq.ra;meta.mainindexedDEJ2000Declination (J2000.0)degpos.eq.dec;meta.mainindexedmF336WF336W STMAG magnitudemagphot.mag;em.opt.Ufloate_mF336WError on F336W magnitudemagstat.errorfloats_mF336WR.M.S on F336W magnitude measurementsmagstat.errorfloatmF343NF343N STMAG magnitudemagphot.mag;em.opt.Ufloate_mF343NError on F343N magnitudemagstat.errorfloats_mF343NR.M.S on F343N magnitude measurementsmagstat.errorfloatmF438WF438W STMAG magnitudemagphot.mag;em.opt.Bfloate_mF438WError on F438W magnitudemagstat.errorfloatmF555WF555W STMAG magnitudemagphot.mag;em.opt.Vfloate_mF555WError on F555W magnitudemagstat.errorfloate_mF606WError on F606W magnitudemagstat.errorfloatmF814WF814W STMAG magnitudemagphot.mag;em.opt.Ifloate_mF814WError on F814W magnitudemagstat.errorfloatmF850LPF850LP STMAG magnitudemagphot.mag;em.opt.Ifloate_mF850LPError on F850LP magnitudemagstat.errorfloatCCD15078[1/2] CCD for GO-15078 datameta.idintCCD11903[1/2] CCD for GO-11903 datameta.idintchi438ALLFRAME chi-square for F438W fitmeta.notefloat