Stellar Populations in the Central 0.5 pc of the Galaxy II: The Initial Mass Function

Abstract

The supermassive black hole at the center of the Milky Way plays host to a massive, young cluster that may have formed in one of the most inhospitable environments in the Galaxy. We present new measurements of the global properties of this cluster, including the initial mass function (IMF), age, and cluster mass. These results are based on Keck laser-guide-star adaptive optics observations used to identify the young stars and measure their Kp-band luminosity function as presented in Do et al. 2013. A Bayesian inference methodology is developed to simultaneously fit the global properties of the cluster utilizing the observations and extensive simulations of synthetic star clusters. We find that the slope of the mass function for this cluster is α= 1.7 +/- 0.2, which is steeper than previously reported, but still flatter than the traditional Salpeter slope of 2.35. The age of the cluster is between 2.5-5.8 Myr with 95% confidence, which is a younger age than typically adopted but consistent within the uncertainties of past measurements. The exact age of the cluster is difficult to determine since our results show two distinct age solutions (3.9 Myr and 2.8 Myr) due to model degeneracies in the relative number of Wolf-Rayet and OB stars. The total cluster mass is between 14,000 - 37,000 \msun above 1 \msun and it is necessary to include multiple star systems in order to fit the observed luminosity function and the number of observed Wolf-Rayet stars. The new IMF slope measurement is now consistent with X-ray observations indicating a factor of 10 fewer X-ray emitting pre-main-sequence stars than expected when compared with a Salpeter IMF. The young cluster at the Galactic center is one of the few definitive examples of an IMF that deviates significantly from the near-universal IMFs found in the solar neighborhood.

accepted to ApJ

References in corpus (24)

• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• The High Angular Resolution Multiplicity of Massive Stars
• A Minimum Column Density of 1 g cm^-2 for Massive Star Formation
• Inverse dynamical population synthesis: Constraining the initial conditions of young stellar clusters by studying their binary populations
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• Simulations of star formation in a gaseous disc around sgr A* - a failed AGN
• Clues to Nuclear Star Cluster Formation from Edge-on Spirals
• Implications of the metallicity dependence of Wolf-Rayet winds
• Chemical Abundances of Luminous Cool Stars in the Galactic Center from High-Resolution Infrared Spectroscopy
• Self-gravitating accretion disk in Sgr A* few million years ago: was Sgr A* a failed quasar?
• Binary Stars in the Orion Nebula Cluster
• Simulations of the formation of stellar discs in the Galactic centre via cloud-cloud collisions
• Stellar Populations in the Central 0.5 pc of the Galaxy I: A New Method for Constructing Luminosity Functions and Surface-Density Profiles
• Multiple protostellar systems. II. A high resolution near-infrared imaging survey in nearby star-forming regions
• A Multiplicity Census of Young Stars in Chamaeleon I
• On the nature of the fast moving star S2 in the Galactic Center
• Exploring the consequences of pairing algorithms for binary stars
• Hypervelocity Stars III. The Space Density and Ejection History of Main Sequence Stars from the Galactic Center
• Multiple Star Formation to the Bottom of the IMF
• The influence of multiple stars on the high-mass stellar initial mass function and age-dating of young massive star clusters
• Stellar dynamical evidence against a cold disc origin for stars in the Galactic Centre
• Multiplicity of young stars in and around R Corona Australis
• Biases on initial mass function determinations. II. Real multiple systems and chance superpositions
• The Distribution of Stellar Mass in the Pleiades

Cited by in corpus (232)

• Assisted Inspirals of Stellar Mass Black Holes Embedded in AGN Disks: Solving the "Final AU Problem"
• Cool Outflows in Galaxies and their Implications
• Formation and Evolution of Compact Object Binaries in AGN Disks
• Fundamental Physics with the Square Kilometre Array
• Nuclear Star Clusters
• Global Hierarchical Collapse In Molecular Clouds. Towards a Comprehensive Scenario
• Improving the open cluster census. II. An all-sky cluster catalogue with Gaia DR3
• The Big Problems in Star Formation: the Star Formation Rate, Stellar Clustering, and the Initial Mass Function
• Stars, Gas, and Dark Matter in the Solar Neighborhood
• Surface Brightness Profile of the Milky Way's Nuclear Star Cluster
• Black hole and neutron star mergers in galactic nuclei
• Merging Binaries in the Galactic Center: The eccentric Kozai-Lidov mechanism with stellar evolution
• Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center
• Greatly enhanced merger rates of compact-object binaries in non-spherical nuclear star clusters
• AGN Disks Harden the Mass Distribution of Stellar-mass Binary Black Hole Mergers
• Improved Dynamical Constraints on the Masses of the Central Black Holes in Nearby Low-mass Early-type Galactic Nuclei And the First Black Hole Determination for NGC 205
• Stellar Dynamics and Stellar Phenomena Near A Massive Black Hole
• Eccentric Black Hole Gravitational-Wave Capture Sources in Galactic Nuclei: Distribution of Binary Parameters
• Black hole, neutron star and white dwarf merger rates in AGN disks
• The 1.28 GHz MeerKAT Galactic Center Mosaic
• The Great Escape: Discovery of a nearby 1700 km/s star ejected from the Milky Way by Sgr A*
• The Dawes Review 8: Measuring the Stellar Initial Mass Function
• Spin Evolution of Stellar-mass Black Hole Binaries in Active Galactic Nuclei
• The XMM-Newton view of the central degrees of the Milky Way
• Twelve years of spectroscopic monitoring in the Galactic Center: the closest look at S-stars near the black hole
• Stellar Populations in the Central 0.5 pc of the Galaxy I: A New Method for Constructing Luminosity Functions and Surface-Density Profiles
• An Overabundance of Black Hole X-Ray Binaries in the Galactic Center from Tidal Captures
• Stellar populations and star formation histories of the nuclear star clusters in six nearby galaxies
• The evolution of CNO isotopes: the impact of massive stellar rotators
• Efficiently Cooled Stellar Wind Bubbles in Turbulent Clouds I. Fractal Theory and Application to Star-Forming Clouds
• The Milky Way's nuclear star cluster: Old, metal-rich, and cuspy
• The Unusual Initial Mass Function of the Arches Cluster
• The distribution of old stars around the Milky Way's central black hole I: Star counts
• The nuclear cluster of the Milky Way: Our primary testbed for the interaction of a dense star cluster with a massive black hole
• The Nuclear Cluster of the Milky Way: Total Mass and Luminosity (long version)
• ALMA-IMF I -- Investigating the origin of stellar masses: Introduction to the Large Program and first results
• 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
• The Fate of Binaries in the Galactic Center: The Mundane and the Exotic
• Improved Dynamical Constraints on the Mass of the central Black Hole in NGC 404
• Secular Evolution Of Binaries Near Massive Black Holes: Formation of compact binaries, merger/collision products and G2-like objects
• Fossil imprint of a powerful flare at the Galactic Centre along the Magellanic Stream
• The MEGaN project II. Gravitational waves from intermediate mass- and binary black holes around a supermassive black hole
• Massive binaries in the vicinity of Sgr A*
• The Structure of Nuclear Star Clusters in Nearby Late-type Spiral Galaxies from Hubble Space Telescope Wide Field Camera 3 Imaging
• A population of dust-enshrouded objects orbiting the Galactic black hole
• The Peculiar Pulsar Population of the Central Parsec
• High Eccentricities and High Masses Characterize Gravitational-wave Captures in Galactic Nuclei as Seen by Earth-based Detectors
• Radio Continuum Observations of the Galactic Center: Photoevaporative Proplyd-like Objects near Sgr A*
• The Proper Motion of the Galactic Center Pulsar Relative to Sagittarius A*
• The First Hypervelocity Star from the LAMOST Survey
• A remarkable Ruby: Absorption in dense gas, rather than evolved stars, drives the extreme Balmer break of a Little Red Dot at $z=3.5$
• New constraints on the structure of the nuclear stellar cluster of the Milky Way from star counts and MIR imaging
• The young stars in the Galactic Center
• A hidden friend for the galactic center black hole, Sgr A*
• Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey
• The influence of circumnuclear environment on the radio emission from TDE jets
• CMZoom: Survey Overview and First Data Release
• Numerical simulations of the possible origin of the two sub-parsec scale and counter-rotating stellar disks around SgrA*
• Star Formation Regulation and Self-Pollution by Stellar Wind Feedback
• ATCA Survey of Ammonia in the Galactic Center: The Temperatures of Dense Gas Clumps between SgrA* and SgrB2
• ALMA-IMF. V. Prestellar and protostellar core populations in the W43 cloud complex
• Merging stellar and intermediate-mass black holes in dense clusters: implications for LIGO, LISA and the next generation of gravitational wave detectors
• Can stellar-mass black hole growth disrupt disks of active galactic nuclei? The role of mechanical feedback
• The Origin of the Stellar Mass Distribution and Multiplicity
• SPISEA: A Python-Based Simple Stellar Population Synthesis Code for Star Clusters
• Kinematic Structure of the Galactic Center S-cluster
• The Hills Mechanism and the Galactic Center S-stars
• Detection of astrophysical gravitational wave sources by TianQin and LISA
• Quiescent and active galactic nuclei as factories of merging compact objects in the era of gravitational-wave astronomy
• Accretion-Induced Collapse of Neutron Stars in the Disks of Active Galactic Nuclei
• ISM Processing in the Inner 20 pc in Galactic center
• ALMA-IMF VI -- Investigating the origin of stellar masses: Core mass function evolution in the W43-MM2&MM3 mini-starburst
• Mapping the Outer Edge of the Young Stellar Cluster in the Galactic Center
• Improved Cosmic-Ray Injection Models and the Galactic Center Gamma-Ray Excess
• Predicting the hypervelocity star population in Gaia
• Testing the role of environmental effects on the initial mass function of low-mass stars
• The Combined Effects of Two-Body Relaxation Processes and the Eccentric Kozai-Lidov Mechanism on the EMRI Rate
• A rapid evolving region in the Galactic Center: Why S-stars thermalize and more massive stars are missing
• Spectroscopic Detection of a Cusp of Late-type Stars around the Central Black Hole in the Milky Way
• Feedback-Dominated Accretion Flows
• The Star Formation History of the Milky Way's Nuclear Star Cluster
• Constraining the dark cusp in the Galactic Center by long-period binaries
• A New Perspective of the Radio Bright Zone at The Galactic Center: Feedback from Nuclear Activities
• Observation of S4716 -- a Star with a 4 yr Orbit around Sgr A*
• Outflows from Super Star Clusters in the Central Starburst of NGC253
• Gaia DR3 in 6D: The search for fast hypervelocity stars and constraints on the Galactic Centre environment
• A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. II. Kinematic characterization of the stellar populations
• Confusing binaries: the role of stellar binaries in biasing disk properties in the Galactic Center
• The orbital motion of the Quintuplet cluster - a common origin for the Arches and Quintuplet clusters?
• On Socially Distant Neighbors: Using Binaries to Constrain the Density of Objects in the Galactic Center
• The low-mass population in the young cluster Stock 8: Stellar properties and Initial Mass Function
• A Critical Reevaluation of Radio Constraints on Annihilating Dark Matter
• On the origin of the B-stars in the Galactic center
• Where intermediate-mass black holes could hide in the Galactic Centre: A full parameter study with the S2 orbit
• Disentangling the formation mechanisms of nuclear star clusters
• Revealing the Formation of the Milky Way Nuclear Star Cluster via Chemo-Dynamical Modeling
• Capture of stars into gaseous discs around massive black holes: Alignment, circularization and growth
• ALMA-IMF XV: The core mass function in the high-mass star-formation regime
• The Galactic Center: Improved Relative Astrometry for Velocities, Accelerations, and Orbits near the Supermassive Black Hole
• 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
• Evidence for the preferential disruption of moderately massive stars by supermassive black holes
• The Keplerian three-body encounter I. Insights on the origin of the S-stars and the G-objects in the Galactic center
• Can supernova kicks trigger EMRIs in the Galactic Centre?
• The Galactic Center as a laboratory for theories of gravity and dark matter
• On the Existence of Pulsars in the Vicinity of the Massive Black Hole in the Galactic Center
• Probing the spinning of the massive black hole in the Galactic Center via pulsar timing: A Full Relativistic Treatment
• Age spreads and the temperature dependence of age estimates in Upper Sco
• Massive binary star mergers in galactic nuclei: implications for blue stragglers, binary S-stars and gravitational waves
• Strong dependence of the physical properties of cores on spatial resolution in observations and simulations
• Characterizing and Improving the Data Reduction Pipeline for the Keck OSIRIS Integral Field Spectrograph
• Tidal disruption events in post-starburst galaxies: the importance of a complete stellar mass function
• CMZoom II: Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone
• An Adaptive Optics Survey of Stellar Variability at the Galactic Center
• Supernova Kicks and Dynamics of Compact Remnants in the Galactic Centre
• Young cluster Berkeley 59 : Properties, evolution and star formation
• Modelling the formation of the circumnuclear ring in the Galactic centre
• The Quintuplet Cluster: Extended Structure and Tidal Radius
• A Stability Timescale for Non-Hierarchical Three-Body Systems
• Star Formation and Dynamics in the Galactic Centre
• The role of the turbulence driving mode for the Initial Mass Function
• Open clusters and associations in the Gaia era
• Properties of bow-shock sources at the Galactic center
• Galactic Center Mini-spiral by ALMA - Possible Origin of the Central Cluster
• Constraints on the Galactic Centre environment from Gaia hypervelocity stars
• The Cosmic Microwave Background and the Stellar Initial Mass Function
• Star formation at the Galactic Centre: coevolution of multiple young stellar discs
• Constraining a companion of the galactic center black hole, Sgr A*
• Impact of initial mass functions on the dynamical channel of gravitational wave sources
• A population of compact radio variables and transients in the radio bright zone at the Galactic center observed with the Jansky Very Large Array
• Stellar Populations in the Central 0.5 pc of Our Galaxy III: The Dynamical Sub-structures
• Perturbations induced by a molecular cloud on the young stellar disc in the Galactic Centre
• A binary system in the S cluster close to the supermassive black hole Sagittarius A*
• Hot Molecular Gas in the Circumnuclear Disk
• Two-body relaxation driven evolution of the young stellar disc in the Galactic Centre
• ALMA-IMF X -- The core population in the evolved W33-Main (G012.80) protocluster
• The properties of hypervelocity stars and S-stars originating from an eccentric disc around a supermassive black hole
• Constraints on the Galactic Centre environment from \textit{Gaia} hypervelocity stars III: Insights on a possible companion to Sgr A*
• Comparing hypervelocity star populations from the Large Magellanic Cloud and the Milky Way
• Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow
• Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre I. Catalog of Variable Sources
• Constraints on the Galactic Centre environment from Gaia hypervelocity stars II: The evolved population
• A numerical study of stellar discs in galactic nuclei
• The galaxy-wide stellar initial mass function in the presence of cluster-to-cluster IMF variations
• The Inner 2 pc of Sagittarius A*: Simulations of the Circumnuclear Disk and Multiphase Gas Accretion in the Galactic Center
• Testing space-time geometries and theories of gravity at the Galactic Center with pulsar's time delay
• The Swansong of the Galactic Center Source X7: An Extreme Example of Tidal Evolution near the Supermassive Black Hole
• The evolution of circumstellar discs in the Galactic Centre: an application to the G-clouds
• On the origin of the central 1" hole in the stellar disk of Sgr A* and the Fermi gamma-ray bubbles
• Mass Segregation in Eccentric Nuclear Disks: Enhanced Tidal Disruption Event Rates for High Mass Stars
• The fate of supernova remnants near quiescent supermassive black holes
• Mass ratio, the hills mechanism, and the galactic centre S-stars
• Testing the Black Hole No-hair Theorem with Galactic Center Stellar Orbits
• Evolution of rotating massive stars with new hydrodynamic wind models
• Detection of a dense group of hyper-compact radio sources in the central parsec of the Galaxy
• Virial Clumps in Central Molecular Zone Clouds
• Spectroscopically Identified Intermediate Age Stars at 0.5 - 3 pc Distance from Sgr A*
• Fiery Cores: Bursty and Smooth Star Formation Distributions across Galaxy Centers in Cosmological Zoom-in Simulations
• Does the SN rate explain the very high energy cosmic rays in the central 200 pc of our Galaxy?
• Is "Dark Energy" a Quantum Vacuum Energy?
• The influence of dense gas rings on the dynamics of a stellar disk in the Galactic center
• The APOGEE Library of Infrared SSP Templates (A-LIST): High-Resolution Simple Stellar Population Spectral Models in the H-Band
• Multi-phase environment of compact galactic nuclei: the role of the Nuclear Star Cluster
• Subaru Hyper Suprime-Cam Survey of Cygnus OB2 Complex -- I: Introduction, Photometry and Source Catalog
• Constraints on the origins of hypervelocity stars: velocity distribution, mergers and star-formation history
• The mean free path approximation and stellar collisions in star clusters: Numerical exploration of the analytic rates and the role of perturbations on binary star mergers
• What Determines the Maximum Mass of AGN-assisted Black Hole Mergers?
• Black Hole Discs and Spheres in Galactic Nuclei -- Exploring the Landscape of Vector Resonant Relaxation Equilibria
• Forming Young and Hypervelocity Stars in the Galactic Centre via Tidal Disruption of a Molecular Cloud
• GCIRS 7, a pulsating M1 supergiant at the Galactic centre. Physical properties and age
• X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr~A*
• Photometric Classification of Stars Around the Milky Way's Central Black Hole: I. Central Parsec
• Probing the vector charge of Sagittarius A* with pulsar timing
• A spectroscopic map of the Galactic centre -- Observations and resolved stars
• Near-identical star formation rate densities from H$\alpha$ and FUV at redshift zero
• McFACTS II: Mass Ratio--Effective Spin Relationship of Black Hole Mergers in the AGN Channel
• Metal abundances in the MACER simulations of the hot interstellar medium
• Evolution of eccentric stellar disks around supermassive black holes: the complex disk disruption dynamics and the milliparsec stars
• Evidence for globular cluster collapse after a dwarf-dwarf merger: A potential nuclear star cluster in formation
• The formation of globular clusters with top-heavy initial mass functions
• A common origin for the circumnuclear disc and the nearby molecular clouds in the Galactic Centre
• Adding a Suite of Chemical Abundances to the MACER Code for the Evolution of Massive Elliptical Galaxies
• The High Mass Slope of the IMF
• Chandra X-ray Measurement of Gas-phase Heavy Element Abundances in the Central Parsec of the Galaxy
• The InfraRed Imaging Spectrograph (IRIS) for TMT: Overview of innovative science programs
• Growing a nuclear star cluster from star formation and cluster mergers: The JWST NIRSpec view of NGC 4654
• Sculpting the Stellar Cusp in the Galactic Center
• Intrinsically Polarized Stars and Implication for Star Formation in the Central Parsec of Our Galaxy
• The influence of the cloud virial parameter on the initial mass function
• 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*
• Tidal disruption rate suppression by the event horizon of spinning black holes
• The S stars' zone of avoidance in the Galactic center
• HCN $J$=4-3, HNC $J$=1-0, ${\mathrm{H}}^{13}\mathrm{CN}$ $J$=1-0, and $\mathrm{H}{\mathrm{C}}_3\mathrm{N}$ $J$=10-9 Maps of Galactic Center Region II.: Physical Properties of Dense Gas Clumps and Probability of Star Formation
• A Novel Survey for Young Substellar Objects with the W-band filter III: Searching for very low mass brown dwarfs in Serpens South and Serpens Core
• The former companion of the hyper-velocity star S5-HVS1
• A stream of hypervelocity stars from the Galactic Center
• Hydrodynamic Evolution of Sgr A East: The Imprint of A Supernova Remnant in the Galactic Center
• The contribution of young core-collapse supernova remnants to the X-ray emission near quiescent supermassive black holes
• Double progenitor origin of the S-star cluster
• An Observational Perspective of the IMF: Progress and Challenges
• Regularized 3D spectroscopy with CubeFit: method and application to the Galactic Center Circumnuclear disk
• Detecting hot stars in the Galactic centre with combined near- and mid-infrared photometry
• Axion signals from neutron star populations
• Ultra High Energy Neutrino Event KM3-230213A as a Signal of Electroweak Vacuum Turbulence in Merging Black Hole Binaries
• Chandra X-ray Measurement of Heavy Element Abundances of Wolf-Rayet Stars in the Galactic Center
• Galactic Traversability: A New Concept for Extragalactic SETI
• A study of the central stellar populations of galaxies in SDSS-IV MaNGA: identification of a sub-sample with unusually young and massive stars
• A multi-frequency, multi-epoch radio continuum study of the Arches cluster with the VLA
• A Recent Supermassive Black Hole Binary in the Galactic Center Unveiled by the Hypervelocity Stars
• The fragmentation of molecular clouds in starburst environments
• The Near-Infrared Spectrum of the Nuclear Star Cluster: Looking Below the Tip of the Iceberg and Comparisons with Extragalactic Nuclei
• Co-evolution of Nuclear Star Clusters and Massive Black Holes: Extreme Mass-Ratio Inspirals
• On the Origin of Young Stars at the Galactic Center
• MUSE IFU observations of galaxies hosting Tidal Disruption Events
• Supernovae in massive binaries and compact object mergers near supermassive black holes
• Observational constraints on the formation and evolution of the Milky Way nuclear star cluster with Keck and Gemini
• Mass flows in the Galactic Center by supernovae of the circumnuclear disk
• Gas Inflow and Star Formation near Supermassive Black Holes: The Role of Nuclear Activity
• Structure and Dynamics of the Young Massive Star Cluster Westerlund 1
• DELVE-ing into the Milky Way's Globular Clusters: Assessing extra-tidal features in NGC 5897, NGC 7492, and testing detectability with deeper photometry
• The Milky Way's nuclear star cluster and massive black hole
• A study of 1000 galaxies with unusually young and massive stars in the SDSS: a search for hidden black holes
• Tidal phenomena in the Galactic Center: The curious case of X7
• Constraining the Variability and Binary Fraction of Galactic Center Young Stars
• Revisiting the Evolutionary Status of Massive Stars at the central parsec of the Milky Way
• Kozai-driven mass loss of the circumbinary disk in D9 in orbit around the supermassive black hole Sgr A*
• Massive star clusters detected by JWST as natural birth places to form intermediate-mass black holes
• On the coupled origin of the stellar IMF and multiplicity
• A solution to the paradox of youth in the Galactic centre
• Neutron-capture elements record the ordered chemical evolution of the disc over time
• Gauging the Impact of Cosmic Ray Feedback on the Stellar Initial Mass Function
• Black Hole Survival Guide: Searching for Stars in the Galactic Center That Endure Partial Tidal Disruption