The Star Formation History of the Milky Way's Nuclear Star Cluster

Abstract

We report the first star formation history study of the Milky Way's nuclear star cluster (NSC) that includes observational constraints from a large sample of stellar metallicity measurements. These metallicity measurements were obtained from recent surveys from Gemini and VLT of 770 late-type stars within the central 1.5 pc. 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%$\pm$3% of the mass, is metal-rich ($\overline{[M/H]}\sim$0.45), and has an age of 5${}_{-2}^{+3}$ Gyr, which is $\sim$3 Gyr younger than earlier studies with fixed (solar) metallicity; this younger age challenges co-evolutionary models in which the NSC and supermassive black holes formed simultaneously at early times. The minor population component has low metallicity ($\overline{[M/H]}\sim$ -1.1) and contains $\sim$7% of the stellar mass. The age of the minor component is uncertain (0.1 - 5 Gyr old). Using the estimated parameters, we infer the following NSC stellar remnant population (with $\sim$18% uncertainty): 1.5$\times$10${}^5$ neutron stars, 2.5$\times$10${}^5$ stellar mass black holes (BHs) and 2.2$\times$10${}^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 (0.01-3 Gpc${}^{-3}$yr${}^{-1}$).

arXiv comment37 pages, 23 figures, Accepted to ApJ

References in corpus (109)

• Observation of Gravitational Waves from a Binary Black Hole Merger
• On the variation of the Initial Mass Function
• GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2
• GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence
• How Massive Single Stars End their Life
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• Mass-loss predictions for O and B stars as a function of metallicity
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• GW170608: Observation of a 19-solar-mass Binary Black Hole Coalescence
• Mind your Ps and Qs: the Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars
• Binary Black Hole Mergers in the first Advanced LIGO Observing Run
• Compact Remnant Mass Function: Dependence on the Explosion Mechanism and Metallicity
• A geometric distance measurement to the Galactic Center black hole with 0.3% uncertainty
• Formation of Supermassive Black Holes
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• Black hole mergers in the universe
• Rapid and Bright Stellar-mass Binary Black Hole Mergers in Active Galactic Nuclei
• Gravitational waves from scattering of stellar-mass black holes in galactic nuclei
• Assisted Inspirals of Stellar Mass Black Holes Embedded in AGN Disks: Solving the "Final AU Problem"
• GW150914: First results from the search for binary black hole coalescence with Advanced LIGO
• Relativistic redshift of the star S0-2 orbiting the Galactic center supermassive black hole
• Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. V. Evidence for a wide age distribution and a complex MDF
• The Nuclear Bulge of the Galaxy. III. Large-Scale Physical Characteristics of Stars and Interstellar Matter
• Age and Metallicity Distribution of the Galactic Bulge from Extensive Optical and Near-IR Stellar Photometry
• Secular evolution of compact binaries near massive black holes: gravitational wave sources and other exotica
• High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data IV: Luminosity Function from the Fall Equatorial Stripe Sampl
• On the Eccentricity Distribution of Coalescing Black Hole Binaries Driven by the Kozai Mechanism in Globular Clusters
• Nuclear Star Clusters
• A Fundamental Relation Between Compact Stellar Nuclei, Supermassive Black Holes, and Their Host Galaxies
• Binary Mergers and Growth of Black Holes in Dense Star Clusters
• Stellar Populations in the Central 0.5 pc of the Galaxy II: The Initial Mass Function
• The Supernova Channel of Super-AGB Stars
• Black Hole Mergers in Galactic Nuclei Induced by the Eccentric Kozai-Lidov Effect
• Interstellar Extinction Law in the J, H, and Ks Bands toward the Galactic Center
• High Resolution Study of Presupernova Compactness
• The Luminosity, Stellar Mass, and Number Density Evolution of Field Galaxies of Known Morphology from z = 0.5 - 3
• Quantifying the Coexistence of Massive Black Holes and Dense Nuclear Star Clusters
• Strong mass segregation around a massive black hole
• AINUR: Atlas of Images of NUclear Rings
• Black hole triple dynamics: breakdown of the orbit average approximation and implications for gravitational wave detections
• Surface Brightness Profile of the Milky Way's Nuclear Star Cluster
• The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass
• Masses and Scaling Relations for Nuclear Star Clusters, and their Coexistence with Central Black Holes
• Massive Black Holes in Star Clusters. II. Realistic Cluster Models
• Merging Binaries in the Galactic Center: The eccentric Kozai-Lidov mechanism with stellar evolution
• Host Galaxies Catalog Used in LIGO Searches for Compact Binary Coalescence Events
• An Extended Star Formation History for the Galactic Center from Hubble Space Telescope/NICMOS Observations
• Greatly enhanced merger rates of compact-object binaries in non-spherical nuclear star clusters
• High angular resolution integral-field spectroscopy of the Galaxy's nuclear cluster: a missing stellar cusp?
• The star formation history of the Milky Way's Nuclear Star Cluster
• Origin and growth of nuclear star clusters around massive black holes
• On the Origin of Nuclear Star Clusters in Late Type Spiral Galaxies
• Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
• Really Cool Stars and the Star Formation History at the Galactic Center
• Dynamical formation signatures of black hole binaries in the first detected mergers by LIGO
• The Role of the Kozai-Lidov Mechanism in Black Hole Binary Mergers in Galactic Centers
• Evidence for a Long-Standing Top-Heavy IMF in the Central Parsec of the Galaxy
• Early formation and recent starburst activity in the nuclear disc of the Milky Way
• Repeated Bursts from Relativistic Scattering of Compact Objects in Galactic Nuclei
• An Overabundance of Black Hole X-Ray Binaries in the Galactic Center from Tidal Captures
• Simulations of the Milky Way's central molecular zone -- I. Gas dynamics
• The Milky Way's nuclear star cluster: Old, metal-rich, and cuspy
• The Unusual Initial Mass Function of the Arches Cluster
• KMOS view of the Galactic Centre - II. Metallicity distribution of late-type stars
• Discovery of low-metallicity stars in the central parsec of the Milky Way
• KMOS view of the Galactic Centre I. Young stars are centrally concentrated
• Mass inflow rate into the Central Molecular Zone: observational determination and evidence of episodic accretion
• GALACTICNUCLEUS: A high angular resolution $JH{K}_s$ imaging survey of the Galactic Centre. I. Methodology, performance, and near-infrared extinction towards the Galactic Centre
• Million-Body Star Cluster Simulations: Comparisons between Monte Carlo and Direct $N$-body
• The inside-out formation of nuclear discs and the absence of old central spheroids in barred galaxies of the TIMER survey
• Are nuclear star clusters the precursors of massive black holes?
• An Accurate, Easy to Use Abundace Scale for Globular Clusters Based on 2.2um Spectra of Giant Stars
• Tidal break-up of binary stars at the Galactic center and its consequences
• Analysis of old very metal rich stars in the solar neighbourhood
• New constraints on the structure of the nuclear stellar cluster of the Milky Way from star counts and MIR imaging
• Constraints on the Stellar Mass Function from Stellar Dynamics at the Galactic Center
• A 6.5-GHz Multibeam Pulsar Survey
• The Milky Way's nuclear stellar disc: A dynamically cool and metal-rich component formed from the Central Molecular Zone?
• Detailed Abundances for the Old Population near the Galactic Center: I. Metallicity distribution of the Nuclear Star Cluster
• Super-Solar Metallicity Stars in the Galactic Center Nuclear Star Cluster: Unusual Sc, V, and Y Abundances
• SPISEA: A Python-Based Simple Stellar Population Synthesis Code for Star Clusters
• The Bulge Metallicity Distribution from the APOGEE Survey
• Mapping the Outer Edge of the Young Stellar Cluster in the Galactic Center
• Star formation history and metallicity in the Galactic inner bulge revealed by the red giant branch bump
• Constraining the initial mass function of stars in the Galactic Centre
• Detailed abundances in the Galactic center: Evidence of a metal-rich alpha-enhanced stellar population
• Chemical Abundances of M giants in the Galactic Center: a Single Metal-Rich Population with Low [alpha/Fe]
• Asymmetric spatial distribution of sub-solar metallicity stars in the Milky Way nuclear star cluster
• On the origin of a rotating metal-poor stellar population in the Milky Way Nuclear Cluster
• On Socially Distant Neighbors: Using Binaries to Constrain the Density of Objects in the Galactic Center
• Revealing the Formation of the Milky Way Nuclear Star Cluster via Chemo-Dynamical Modeling
• Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre II. Identification of RR Lyrae Stars in the Milky Way Nuclear Star Cluster
• The X-ray binary population in the Galactic Center revealed through multi-decade observations
• Caught in formation: the nuclear-cluster-to-be in NGC 2139
• The nuclear star cluster and nuclear stellar disc of the Milky Way: Different stellar population and star formation history
• Chemical evolution of the Galactic Center
• Searching for pulsars in the Galactic Centre at 3 and 2 mm
• Stellar Populations in the Transition Region of Nuclear Star Cluster and Nuclear Stellar Disc
• Kinematic data rebuild the Nuclear star cluster as the most metal rich region of the Galaxy
• The Impact of Initial-Final Mass Relations on Black Hole Microlensing
• Measuring the alpha-abundance of subsolar-metallicity stars in the Milky Way's central half-parsec: testing globular cluster and dwarf galaxy infall scenarios

Cited by in corpus (18)

• Exploring dark matter spike distribution around the Galactic centre with stellar orbits
• Massive black hole assembly in nuclear star clusters
• Predictions of a simple parametric model of hierarchical black hole mergers
• Milky Way White Dwarfs as Sub-GeV to Multi-TeV Dark Matter Detectors
• The formation history of our Galaxy's nuclear stellar disc constrained from HST observations of the Quintuplet field
• Smooth kinematic and metallicity gradients reveal that the Milky Way's nuclear star cluster and disc might be part of the same structure
• Milky Way globular clusters on cosmological timescales. II. Interaction with the Galactic centre
• A spectroscopic map of the Galactic centre -- Observations and resolved stars
• Chandra X-ray Measurement of Gas-phase Heavy Element Abundances in the Central Parsec of the Galaxy
• Growing a nuclear star cluster from star formation and cluster mergers: The JWST NIRSpec view of NGC 4654
• Candidate Young Stellar Objects in the S-cluster: The Kinematic Analysis of a Sub-population of the Low-mass G-objects close to Sgr A*
• A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster
• Double progenitor origin of the S-star cluster
• Age and metallicity of the Milky Way's nuclear star cluster studied at 3 pc from Sagittarius A*
• Dynamical traction and black hole orbital migration
• The Galactic Center with Roman
• Demonstration of Plate Analysis, an algorithm for precise relative astrometry
• Supergiant GCIRS 22 in the Milky Way Nuclear Star Cluster: Revised alpha abundances