The chemical homogeneity of open clusters

Abstract

Determining the level of chemical homogeneity in open clusters is of fundamental importance in the study of the evolution of star-forming clouds and that of the Galactic disk. Yet limiting the initial abundance spread in clusters has been hampered by difficulties in obtaining consistent spectroscopic abundances for different stellar types. Without reference to any specific model of stellar photospheres, a model for a homogeneous cluster is that it forms a one-dimensional sequence, with any differences between members due to variations in stellar mass and observational uncertainties. I present a novel method for investigating the abundance spread in open clusters that tests this one-dimensional hypothesis at the level of observed stellar spectra, rather than constraining homogeneity using derived abundances as traditionally done. Using high-resolution APOGEE spectra for 49 giants in M67, NGC 6819, and NGC 2420 I demonstrate that these spectra form one-dimensional sequences for each cluster. With detailed forward modeling of the spectra and Approximate Bayesian Computation, I derive strong limits on the initial abundance spread of 15 elements: <0.01 (0.02) dex for C and Fe, <~0.015 (0.03) dex for N, O, Mg, Si, and Ni, <~0.02 (0.03) dex for Al, Ca, and Mn, and <~0.03 (0.05) dex for Na, S, K, Ti, and V (at 68% and 95% confidence, respectively). The strong limits on C and O imply that no pollution by massive core-collapse supernovae occurred during star formation in open clusters, which, thus, need to form within <~6 Myr. Further development of this and related techniques will bring the power of differential abundances to stars other than solar twins in large spectroscopic surveys and will help unravel the history of star formation and chemical enrichment in the Milky Way through chemical tagging.

References in corpus (17)

• The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III
• The 2.5 m Telescope of the Sloan Digital Sky Survey
• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• The nucleosynthesis of Al26 and Fe60 in solar metallicity stars extending in mass from 11 to 120 Msun: the hydrostatic and explosive contributions
• The Data Reduction Pipeline for the Apache Point Observatory Galactic Evolution Experiment
• Abundances, Stellar Parameters, and Spectra From the SDSS-III/APOGEE Survey
• The Cannon: A data-driven approach to stellar label determination
• Equilibrium Star Cluster Formation
• The SDSS-III APOGEE Spectral Line List for H-band Spectroscopy
• Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey
• New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE survey
• Chemical Homogeneity in Collinder 261 and Implications for Chemical Tagging
• Chemically Tagging the HR1614 Moving Group
• Early turbulent mixing as the origin of chemical homogeneity in open star clusters
• Testing the chemical tagging technique with open clusters
• The Puzzling Li-rich Red Giant Associated with NGC 6819
• APOGEE chemical tagging constraint on the maximum star cluster mass in the $\alpha$-enhanced Galactic disk

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• Markov Chain Monte Carlo Methods for Bayesian Data Analysis in Astronomy
• The Payne: self-consistent ab initio fitting of stellar spectra
• Accuracy and precision of industrial stellar abundances
• Simultaneous calibration of spectro-photometric distances and the Gaia DR2 parallax zero-point offset with deep learning
• The influence of atomic diffusion on stellar ages and chemical tagging
• Measuring Radial Orbit Migration in the Milky Way Disk
• Discovery and Characterization of 3000+ Main-Sequence Binaries from APOGEE Spectra
• An accurate and self-consistent chemical abundance catalogue for the APOGEE/Kepler sample
• The Hyades open cluster is chemically inhomogeneous
• Identical or fraternal twins? : The chemical homogeneity of wide binaries from Gaia DR2
• The GALAH Survey: Chemical tagging and chrono-chemodynamics of accreted halo stars with GALAH+ DR3 and $Gaia$ eDR3
• Galactic Doppelganger: The chemical similarity among field stars and among stars with a common birth origin
• Chemical Abundances of Main-Sequence, Turnoff, Subgiant and red giant Stars from APOGEE spectra II: Atomic Diffusion in M67 Stars
• In the Galactic disk, stellar [Fe/H] and age predict orbits and precise [X/Fe]
• Metallicity Fluctuation Statistics in the Interstellar Medium and Young Stars. I. Variance and Correlation
• Signatures of unresolved binaries in stellar spectra: implications for spectral fitting
• The chemical compositions of solar twins in the open cluster M67
• Open clusters in APOGEE and GALAH: Combining Gaia and ground-based spectroscopic surveys
• Chemical Abundances of Main-Sequence, Turn-off, Subgiant and red giant Stars from APOGEE spectra I: Signatures of Diffusion in the Open Cluster M67
• The Impact of Metallicity on the Evolution of Rotation and Magnetic Activity of Sun-Like Stars
• Chemodynamical Modelling of the Galactic Bulge and Bar
• Chemical (in)homogeneity and atomic diffusion in the open cluster M67
• The Close Binary Fraction as a Function of Stellar Parameters in APOGEE: A Strong Anti-Correlation With $\alpha$ Abundances
• 3-D gas-phase elemental abundances across the formation histories of Milky Way-mass galaxies in the FIRE simulations: initial conditions for chemical tagging
• Stellar Abundance Maps of the Milky Way Disk
• Prospects for Measuring Abundances of >20 Elements with Low-resolution Stellar Spectra
• The GALAH survey: Chemical Tagging of Star Clusters and New Members in the Pleiades
• Unmixing the Galactic Halo with RR Lyrae tagging
• The Milky Way tomography with APOGEE: intrinsic density distribution and structure of mono-abundance populations
• The homogeneity of the star forming environment of the Milky Way disk over time
• Detecting outliers and learning complex structures with large spectroscopic surveys - a case study with APOGEE stars
• Starspots and Magnetism: Testing the Activity Paradigm in the Pleiades and M67
• The GALAH Survey and Gaia DR2: (Non)existence of five sparse high-latitude open clusters
• Using APOGEE Wide Binaries to Test Chemical Tagging with Dwarf Stars
• Strong chemical tagging with APOGEE: 21 candidate star clusters that have dissolved across the Milky Way disc
• Wide Binaries in Tycho-Gaia II: Metallicities, Abundances, and Prospects for Chemical Tagging
• Open Cluster Chemical Homogeneity Throughout the Milky Way
• The GALAH Survey: Chemical Clocks
• Stars that Move Together Were Born Together
• Mixing of metals during star cluster formation: statistics and implications for chemical tagging
• Fundamental Properties of Co-Moving Stars observed by $Gaia$
• TESS observations of the Pleiades cluster: a nursery for delta Scuti stars
• The (im)possibility of strong chemical tagging
• Host-star and exoplanet compositions: a pilot study usinga wide binary with a polluted white dwarf
• Cosmic variance in [O/Fe] in the Galactic disk
• Blind chemical tagging with DBSCAN: prospects for spectroscopic surveys
• The dimensionality of stellar chemical space using spectra from the Apache Point Observatory Galactic Evolution Experiment
• Planet Engulfment Detections are Rare According to Observations and Stellar Modeling
• The 3-D Kinematics of the Orion Nebula Cluster: NIRSPEC-AO Radial Velocities of the Core Population
• Chemical Abundances in a Sample of Red Giants in the Open Cluster NGC 2420 from APOGEE
• Chemical inhomogeneities in the Pleiades: signatures of rocky-forming material in stellar atmospheres
• Five young $\delta$ Scuti stars in the Pleiades seen with Kepler/K2
• Timing the Evolution of the Galactic Disk with NGC 6791: An Open Cluster with Peculiar High-$\alpha$ Chemistry as seen by APOGEE
• Stellar Population Astrophysics (SPA) with TNG. The old open clusters Collinder 350, Gulliver 51, NGC 7044, and Ruprecht 171
• A Dynamical Model for Clustered Star Formation in the Galactic Disk
• Constructing Polynomial Spectral Models for Stars
• Residual Abundances in GALAH DR3: Implications for Nucleosynthesis and Identification of Unique Stellar Populations
• A2A: 21,000 bulge stars from the ARGOS survey with stellar parameters on the APOGEE scale
• Accelerated Fitting of Stellar Spectra
• A metallicity study of F, G, K and M dwarfs in the Coma Berenices open cluster from the APOGEE survey
• The GALAH survey: Chemical homogeneity of the Orion complex
• Astrophysical properties of 600 bonafide single stars in the Hyades open cluster
• The Chemical Nature of the Young 120-Myr-old Nearby Pisces-Eridanus Stellar Stream Flowing through the Galactic Disk
• From birth associations to field stars: mapping the small-scale orbit distribution in the Galactic disc
• Stellar Parameters and Chemical Abundances Estimated from LAMOST-II DR8 MRS based on Cycle-StarNet
• Disentangled Representation Learning for Astronomical Chemical Tagging
• Machine learning in APOGEE: Identification of stellar populations through chemical abundances
• Progenitor Mass Distribution for 22 Historic Core-Collapse Supernovae
• The GALAH survey: Co-orbiting stars and chemical tagging
• Disentangling the Arcturus stream
• The AMBRE Project: searching for the closest solar siblings
• A data-driven model of nucleosynthesis with chemical tagging in a lower-dimensional latent space
• Benchmarking Gaia DR3 Apsis with the Hyades and Pleiades open clusters
• Searching for Solar Siblings in APOGEE and $Gaia$ DR2 with N-body Simulations
• Chemo-Dynamical Clustering applied to APOGEE data: Re-Discovering Globular Clusters
• The Gaia-ESO Survey: Chemical tagging in the thin disk. Open clusters blindly recovered in the elemental abundance space
• The longevity of the oldest open clusters: Structural parameters of NGC 188, NGC 2420, NGC 2425, NGC 2682, NGC 6791, NGC 6819
• APOGEE/Kepler Overlap Yields Orbital Solutions for a Variety of Eclipsing Binaries
• A collage of small planets from the Lick Carnegie Exoplanet Survey : Exploring the super-Earth and sub-Neptune mass regime
• Testing the chemical homogeneity of chemically tagged dissolved birth clusters
• Searching for the extra-tidal stars of globular clusters using high-dimensional analysis and a core particle spray code
• Chemical Cartography with APOGEE: Two-process Parameters and Residual Abundances for 288,789 Stars from Data Release 17
• A Model RRNet for Spectral Information Exploitation and LAMOST Medium-resolution Spectrum Parameter Estimation
• Disentangling the origin of chemical differences using GHOST
• Reliable stellar abundances of individual stars with the MUSE integral-field spectrograph
• Carbon-enhanced metal-poor stars in the SDSS-APOGEE database
• A GALAH View of the Chemical Homogeneity and Ages of Stellar Strings Identified in Gaia
• Internal calibration of LAMOST and Gaia DR3 GSP-Spec stellar abundances
• Clusters: age scales for stellar physics
• Inferring stellar parameters and their uncertainties from high-resolution spectroscopy using invertible neural networks
• Parameter Estimation of LAMOST Medium-resolution Stellar Spectra
• Measuring Dwarf Galaxy Intrinsic Abundance Scatter with Mid-resolution Spectroscopic Surveys: Calibrating APOGEE Abundance Errors
• A catalogue of asteroseismically calibrated ages for APOGEE DR17. The predictions of a CatBoost machine learning model based on the [Mg/Ce] chemical clock and other stellar parameters
• The GALAH survey: Improving chemical abundances using star clusters
• A baseline on the relation between chemical patterns and birth stellar cluster
• Open cluster members in APOGEE DR17 I. Dynamics and star members
• The dawn is quiet here: Rise in [$\alpha$/Fe] is a signature of massive gas accretion that fueled proto-Milky Way
• Functional Data Analysis for Extracting the Intrinsic Dimensionality of Spectra: Application to Chemical Homogeneity in the Open Cluster M67
• Detailed Abundances of Planet-Hosting Open Clusters. The Praesepe (Beehive) Cluster
• 3D elemental abundances of stars at formation across the histories of Milky Way-mass galaxies in the FIRE simulations