J/A+A/618/A2ivo://CDS.VizieR/J/A+A/618/A2doi:10.26093/cds/vizier.36180002CDSClark J.S.Lohr M.E.Patrick L.R.Najarro F.Dong H.Figer D.F.2019-03-25T13:40:46Z2019-03-14T09:25:40ZCDS support team

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

cds-question@unistra.fropen-star-clustersFound within the central molecular zone, the Quintuplet is one of the most massive young clusters in the Galaxy. As a consequence it offers the prospect of constraining stellar formation and evolution in extreme environments. However, current observations suggest that it comprises a remarkably diverse stellar population that is difficult to reconcile with an instantaneous formation event. To better understand the nature of the cluster our aim is to improve observational constraints on the constituent stars. In order to accomplish this goal we present Hubble Space Telescope/NICMOS+WFC3 photometry and Very Large Telescope/SINFONI+KMOS spectroscopy for ~100 and 71 cluster members, respectively. Spectroscopy of the cluster members reveals the Quintuplet to be far more homogeneous than previously expected. All supergiants are classified as either O7-8 Ia or O9-B0 Ia, with only one object of earlier (O5 I-III) spectral type. These stars form a smooth morphological sequence with a cohort of seven early-B hypergiants and six luminous blue variables and WN9-11h stars, which comprise the richest population of such stars of any stellar aggregate known. In parallel, we identify a smaller population of late-O hypergiants and spectroscopically similar WN8-9ha stars. No further H-free Wolf-Rayet (WR) stars are identified, leaving an unexpectedly extreme ratio of 13:1 for WC/WN stars. A subset of the O9-B0 supergiants are unexpectedly faint, suggesting they are both less massive and older than the greater cluster population. Finally, no main sequence objects were identifiable. Due to uncertainties over which extinction law to apply, it was not possible to quantitatively determine a cluster age via isochrone fitting. Nevertheless, we find an impressive coincidence between the properties of cluster members preceding the H-free WR phase and the evolutionary predictions for a single, non-rotating 60M_{sun}_ star; in turn this implies an age of ~3.0-3.6Myr for the Quintuplet. Neither the late O-hypergiants nor the low luminosity supergiants are predicted by such a path; we suggest that the former either result from rapid rotators or are the products of binary driven mass-stripping, while the latter may be interlopers. The H-free WRs must evolve from stars with an initial mass in excess of 60M_{sun}_ but it appears difficult to reconcile their observational properties with theoretical expectations. This is important since one would expect the most massive stars within the Quintuplet to be undergoing core-collapse/SNe at this time; since the WRs represent an evolutionary phase directly preceding this event,their physical properties are crucial to understanding both this process and the nature of the resultant relativistic remnant. As such, the Quintuplet provides unique observational constraints on the evolution and death of the most massive stars forming in the local, high metallicity Universe.2018A&A...618A...2Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/618/A2CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/371/38 : X-ray observations of Arches & Quintuplet (Wang+, 2006)J/A+A/494/1137 : Quintuplet cluster K-band spectral catalog (Liermann+, 2009)J/A+A/540/A57 : Mass function of Quintuplet cluster (Hussmann+, 2012)J/ApJ/789/115 : The Quintuplet cluster astrometry & photometry (Stolte+, 2014)J/A+A/578/A4 : Photometry and motions in Arches & Quintuplet (Stolte+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/618/A2https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/618/A2http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/618/A2https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/618/A2https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/618/A2http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/618/A2GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/618/A2/tablea2 (Stellar population of the Quintuplet cluster)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/618/A2/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/618/A2/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/618/A2/tablea2?GETtext/xml+votable180.050000true266.5730417-28.82472220.005555555555555556Cone search capability for table J/A+A/618/A2/tablea1 (HST photometry of stellar members of the Quintuplet cluster)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/618/A2/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/618/A2/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/618/A2/tablea1?GETtext/xml+votable180.050000true266.56352-28.834250.0055555555555555566/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/618/A2?format=asciidefaultJ/A+A/618/A2/tablea2Stellar population of the Quintuplet clusterSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAllDisplay the data from the 2 tablesmeta.ref.urlcharIDqF number or other name (G1)meta.id;meta.maincharLHO? LHO number (G2)meta.idintnullableRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainClassCMost up-to-date spectral classification available from either Figer at al. (1999ApJ...514..202F) or Liermann et al., 2009, Cat. J/A+A/494/1137)src.classcharClassRRevised classification, this papersrc.classcharNotesNotes (1)meta.notecharJ/A+A/618/A2/tablea1HST photometry of stellar members of the Quintuplet clusterSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAllDisplay the data from the 2 tablesmeta.ref.urlcharIDqF number or other name (1)meta.id;meta.maincharLHO? LHO numbermeta.idintnullableRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainF110W? HST F110W magnitudemagphot.flux.density;em.IR.Jfloatnullablee_F110W? rms uncertainty on F110Wmagstat.errorfloatnullablen_F110W[*] Uncertainty flag on F110Wmeta.notecharF160W? HST F160W magnitudemagphot.mag;em.IR.Hfloatnullablee_F160W? rms uncertainty on F160Wmagstat.errorfloatnullablen_F160W[*] Uncertainty flag on F160Wmeta.notecharF205W? HST F205W magnitudemagphot.mag;em.IR.Kfloatnullablee_F205W? rms uncertainty on F205Wmagstat.errorfloatnullablen_F205W[*] Uncertainty flag on F205Wmeta.notecharF127M? HST F127M magnitudemagphot.mag;em.IR.Jfloatnullablee_F127M? rms uncertainty on F127Mmagstat.errorfloatnullableF139M? HST F139M magnitudemagphot.mag;em.IR.Jfloatnullablee_F139M? rms uncertainty on F139Mmagstat.errorfloatnullableF153M? HST F153M magnitudemagphot.mag;em.IR.Jfloatnullablee_F153M? rms uncertainty on F153Mmagstat.errorfloatnullable