J/ApJ/944/79ivo://CDS.VizieR/J/ApJ/944/79doi:10.26093/cds/vizier.19440079CDSChen Z.Do T.Ghez A.M.Hosek M.W.J.Feldmeier-Krause A.Chu D.S.,Bentley R.O.Lu J.R.Morris M.R.2025-05-21T20:14:55Z2025-02-26T09:20:41ZCDS support team

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

cds-question@unistra.frgalactic-centerlate-type-starschemical-abundancesinfrared-astronomyspectroscopyinfrared-photometrymilky-way-galaxyWe report the first star formation history study of the Milky Ways nuclear star cluster (NSC), which includes observational constraints from a large sample of stellar metallicity measurements. These metallicity measurements were obtained from recent surveys from Gemini and the Very Large Telescope of 770 late-type stars within the central 1.5pc. These metallicity measurements, along with photometry and spectroscopically derived temperatures, are forward modeled with a Bayesian inference approach. Including metallicity measurements improves the overall fit quality, as the low-temperature red giants that were previously difficult to constrain are now accounted for, and the best fit favors a two-component model. The dominant component contains 93%+/-3% of the mass, is metal-rich (\overline{[M/H]}~0.45), and has an age of 5_-2-^+3^Gyr, which is ~3Gyr younger than earlier studies with fixed (solar) metallicity; this younger age challenges coevolutionary models in which the NSC and supermassive black holes formed simultaneously at early times. The minor population component has low metallicity (\overline{[M/H]}~-1.1) and contains ~7% of the stellar mass. The age of the minor component is uncertain (0.1-5Gyr old). Using the estimated parameters, we infer the following NSC stellar remnant population (with ~18% uncertainty): 1.5x10^5^ neutron stars, 2.5x10^5^ stellar-mass black holes (BHs), and 2.2x10^4^ BH-BH binaries. These predictions result in 2-4 times fewer neutron stars compared to earlier predictions that assume solar metallicity, introducing a possible new path to understand the so-called "missing-pulsar problem". Finally, we present updated predictions for the BH- BH merger rates (0.01-3Gpc^-3^/yr).2023ApJ...944...79Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/944/79CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/597/323 : Cool stars at the Galactic Center (Blum+, 2003)J/ApJ/675/1459 : Compact Binary Coalescence Galaxy Catalog (Kopparapu+, 2008)J/ApJ/703/1323 : Sp. of stars in the Galaxy's nuclear cluster (Do+ 2009)J/A+A/511/A18 : NIR observations of stars near SgrA* (Schoedel+, 2010)J/A+A/535/A42 : Metal rich stars in solar neighbourhood (Trevisan+, 2011)J/A+A/549/A147 : Abund. of microlensed bulge dwarf stars. V. (Bensby+, 2013)J/A+A/564/A125 : AGN Torus model comparison in the CDFS (Buchner+, 2014)J/A+A/570/A2 : Spectra and RVs of nuclear stars (Feldmeier+, 2014)J/A+A/566/A47 : MW nuclear star cluster extinction map (Schoedel+, 2014)J/ApJ/809/143 : K-band sp. of stars within central 1pc of the MW (Do+, 2015)J/A+A/584/A2 : KMOS view of the Gal. centre. I. (Feldmeier-Krause+, 2015)J/ApJ/808/106 : NIR sp. obs. in the Galactic Center (Stostad+, 2015)J/MNRAS/457/2122 : Nuclear star clusters photometric masses (Georgiev+, 2016)J/MNRAS/464/194 : Metallicity distribution in the GC (Feldmeier-Krause+, 2017)J/A+A/610/A83 : GALACTICNUCLEUS: JHKs imaging survey (Nogueras-Lara+, 2018)J/MNRAS/494/396 : Metallicity distribution in GC (Feldmeier-Krause+, 2020)J/A+A/641/A102 : MW nuclear star cluster HKs photometry (Schoedel+, 2020)J/MNRAS/513/5920 : Stellar Populations of NSC and NSD (Feldmeier-Krause, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/944/79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/944/79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/944/79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/944/79https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/944/79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/944/79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/944/79/table10 (AO observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/944/79/table10?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/944/79/table10?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/944/79/table10?GETtext/xml+votable180.050000true266.42165611-29.007946940.005555555555555556Cone search capability for table J/ApJ/944/79/table11 (Seeing-limited observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/944/79/table11?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/944/79/table11?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/944/79/table11?GETtext/xml+votable180.050000true266.41675-29.01029610.0055555555555555566/288307.952274030004205e-20 1.0188844282367877e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/944/79?format=asciiInfrareddefaultJ/ApJ/944/79/table10AO observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[SDM2015]Name (1)meta.id;meta.maincharRAJ2000[266.4/266.5] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-29.1/-29] Declination (J2000)degpos.eq.dec;meta.mainKsmag[10.44/16.67] Ks-band magnitude (2)magphot.mag;em.IR.Kfloate_Ksmag[0.01/0.2] Uncertainty in Ksmagmagstat.error;phot.mag;em.IR.KfloatHmag[12.57/18]? H-band magnitude (2)magphot.mag;em.IR.Hfloatnullablee_Hmag[0.01/0.04]? Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableAKs[2.3/3] Extinction correction at Ks-band (2)magphys.absorption;em.IR.KfloatTeff-CO[2980/4851] Effective temperature from CO (G1)Kphys.temperature.effective;em.line.COinte_Teff-CO[164/176] Uncertainty in Teff-COKstat.error;phys.temperature.effective;em.line.COintTeffS[3447/4613] Starkit-derived effective temperature (G2)Kphys.temperature.effectiveinte_TeffS[413/425] Uncertainty in TeffSKstat.error;phys.temperature.effectiveint[M/H][-1.27/0.96] Metallicity (G2)phys.abundfloate_[M/H][0.3/0.4] Uncertainty in [M/H]stat.error;phys.abundfloatS10Display data from Schoedel+ 2010, J/A+A/511/A18 within 0.1"meta.ref.urlintnullableJ/ApJ/944/79/table11Seeing-limited observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[FNS2015][1/25496] Name (1)meta.id;meta.mainintRAJ2000[266.4/266.43] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-29.02/-28.9] Declination (J2000)degpos.eq.dec;meta.mainKsmag[9/16.44] Ks-band magnitude (2)magphot.mag;em.IR.Kfloate_Ksmag[0.01/1] Uncertainty in Ksmagmagstat.error;phot.mag;em.IR.KfloatHmag[11.7/19.01] H-band magnitude (2)magphot.mag;em.IR.Hfloate_Hmag[0.01/1] Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatAKs[2.3/3.6] Extinction correction at Ks-band (2)magphys.absorption;em.IR.KfloatTeff-CO[2181/5466] Effective temperature from CO (G1)Kphys.temperature.effective;em.line.COinte_Teff-CO[163/854] Uncertainty in Teff-COKstat.error;phys.temperature.effective;em.line.COintTeffS[2300/5297] Starkit-derived effective temperature (G2)Kphys.temperature.effectiveinte_TeffS[205/463] Uncertainty in TeffSKstat.error;phys.temperature.effectiveint[M/H][-1.25/1] Metallicity (G2)phys.abundfloate_[M/H][0.24/0.4] Uncertainty in [M/H]stat.error;phys.abundfloatS10Display data from Schoedel+ 2010, J/A+A/511/A18 within 0.1"meta.ref.urlintnullable