Insights from the APOKASC Determination of the Evolutionary State of Red-Giant Stars by consolidation of different methods

Abstract

The internal working of low-mass stars is of great significance to both the study of stellar structure and the history of the Milky Way. Asteroseismology has the power to directly sense the internal structure of stars and allows for the determination of the evolutionary state -- i.e. has helium burning commenced or is the energy generated only by the fusion in the hydrogen-burning shell? We use observational data from red-giant stars in a combination (known as APOKASC) of asteroseismology (from the \textit{Kepler} mission) and spectroscopy (from SDSS/APOGEE). The new feature of the analysis is that the APOKASC evolutionary state determination is based on the comparison of diverse approaches to the investigation of the frequency-power spectrum. The high level of agreement between the methods is a strong validation of the approaches. Stars for which there is not a consensus view are readily identified. The comparison also facilitates the identification of unusual stars including those that show evidence for very strong coupling between p and g cavities. The comparison between the classification based on the spectroscopic data and asteroseismic data have led to a new value for the statistical uncertainty in APOGEE temperatures. These consensus evolutionary states will be used as an input for methods that derive masses and ages for these stars based on comparison of observables with stellar evolutionary models (`grid-based modeling') and as a training set for machine-learning and other data-driven methods of evolutionary state determination

arXiv comment19 pages, 10 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (64)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• The 2.5 m Telescope of the Sloan Digital Sky Survey
• SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
• ASPCAP: The Apogee Stellar Parameter and Chemical Abundances Pipeline
• Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars
• The Data Reduction Pipeline for the Apache Point Observatory Galactic Evolution Experiment
• Target Selection for the Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Asteroseismology of old open clusters with Kepler: direct estimate of the integrated RGB mass loss in NGC6791 and NGC6819
• The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
• Target Selection for the SDSS-IV APOGEE-2 Survey
• APOGEE Data Releases 13 and 14: Data and Analysis
• Red giant masses and ages derived from carbon and nitrogen abundances
• Probing the core structure and evolution of red giants using gravity-dominated mixed modes observed with Kepler
• Asteroseismic classification of stellar populations among 13000 red giants observed by Kepler
• Solar-like oscillations in low-luminosity red giants: first results from Kepler
• Characterization of the power excess of solar-like oscillations in red giants with Kepler
• The APOGEE red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk
• On detecting the large separation in the autocorrelation of stellar oscillation times series
• Theoretical amplitudes and lifetimes of non-radial solar-like oscillations in red giants
• Mixed modes in red giants: a window on stellar evolution
• Spectroscopic determination of masses (and implied ages) for red giants
• Stellar population synthesis based modelling of the Milky Way using asteroseismology of 13000 Kepler red giants
• Tracing chemical evolution over the extent of the Milky Way's Disk with APOGEE Red Clump Stars
• Mixed modes in red-giant stars observed with CoRoT
• Granulation in Red Giants: observations by the Kepler mission and 3D convection simulations
• Period spacings in red giants II. Automated measurement
• Asteroseismology Can Reveal Strong Internal Magnetic Fields in Red Giant Stars
• The universal red-giant oscillation pattern; an automated determination with CoRoT data
• Characteristics of solar-like oscillations in red giants observed in the CoRoT exoplanet field
• Giant star seismology
• A secondary clump of red giant stars: why and where
• A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars
• Measuring the vertical age structure of the Galactic disc using asteroseismology and SAGA
• Evolutionary influences on the structure of red-giant acoustic oscillation spectra from 600d of Kepler observations
• Determining stellar parameters of asteroseismic targets: going beyond the use of scaling relations
• Period spacings in red giants I. Disentangling rotation and revealing core structure discontinuities
• Testing convective-core overshooting using period spacings of dipole modes in red giants
• An accurate and self-consistent chemical abundance catalogue for the APOGEE/Kepler sample
• A multi-site campaign to measure solar-like oscillations in Procyon. II. Mode frequencies
• Surface Activity and Oscillation Amplitudes of Red Giants in Eclipsing Binaries
• Binary stars in the Galactic thick disc
• Cannibals in the thick disk: the young $\alpha -$rich stars as evolved blue stragglers
• Seismic diagnostics of red giants: first comparison with stellar models
• Post first dredge-up [C/N] ratio as age indicator. Theoretical calibration
• Implications of New JHK Photometry and a Deep Infrared Luminosity Function for the Galactic Bulge
• Dipole modes with depressed amplitudes in red giants are mixed modes
• Constraining Metallicity-dependent Mixing and Extra Mixing using [C/N] in Alpha-Rich Field Giants
• Period spacings in red giants IV: Toward a complete description of the mixed-mode pattern
• Deep Learning Classification in Asteroseismology Using an Improved Neural Network: Results on 15000 Kepler Red Giants and Applications to K2 and TESS Data
• Theoretical power spectra of mixed modes in low mass red giant stars
• A New Method for the Asteroseismic Determination of the Evolutionary State of Red-Giant Stars
• Study of KIC 8561221 observed by Kepler: an early red giant showing depressed dipolar modes
• The Gaia-ESO Survey: CNO abundances in the open clusters Trumpler 20, NGC 4815, and NGC 6705
• The treatment of mixing in core helium burning models -- II. Constraints from cluster star counts
• Origin of $\alpha$-rich young stars: clues from C, N and O
• Nitrogen depletion in field red giants: mixing during the He flash?
• Using red clump stars to correct the Gaia DR1 parallaxes
• APOGEE [C/N] Abundances Across the Galaxy: Migration and Infall from Red Giant Ages
• Evidence for compact binary systems around Kepler red giants
• Evolutionary states of red-giant stars from grid-based modelling
• Scaling relations for solar-like oscillations: a review

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• Age dissection of the Milky Way discs: red giants in the Kepler field
• APOKASC-3: The Third Joint Spectroscopic and Asteroseismic catalog for Evolved Stars in the Kepler Fields
• Discovery of post-mass-transfer helium-burning red giants using asteroseismology
• Age-Dating Red Giant Stars Associated with Galactic Disk and Halo Substructures
• Cannibals in the thick disk II -- Radial-velocity monitoring of the young alpha-rich stars
• The K2 Galactic Archaeology Program Data Release 2: Asteroseismic results from campaigns 4, 6, & 7
• A seismic scaling relation for stellar age II: The red giant branch
• Nature vs. Nurture: Distinguishing Effects from Stellar Processing and Chemical Evolution on Carbon and Nitrogen in Red Giant Stars
• The APO-K2 Catalog. II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way
• Is Thermohaline Mixing the Full Story? Evidence for Separate Mixing Events near the Red Giant Branch Bump
• An Intermediate-age Alpha-rich Galactic Population in K2
• Characterizing Observed Extra Mixing Trends in Red Giants using the Reduced Density Ratio from Thermohaline Models
• Clumpiness: Time-domain classification of red-giant evolutionary states
• Unveiling the Structure and Dynamics of Red Giants with Asteroseismology
• Measuring frequency and period separations in red-giant stars using machine learning
• Lithium in Kepler Red Giants: Defining Normal and Anomalous
• Red giants evolutionary status determination: the complete Kepler catalog
• Advancing accuracy in age determinations of old-disk stars using an oscillating red giant in an eclipsing binary
• GaiaUnlimited: The old stellar disc of the Milky Way as traced by the Red Clump
• Power density spectra morphologies of seismically unresolved red-giant asteroseismic binaries
• The sensitivity and behaviour of the curvature in the échelle diagram of red-giant stars
• The highest mass Kepler red giants -- II. Spectroscopic parameters, the amplitude-activity relation, and unexpected halo orbits
• Red giant asteroseismic binaries in the Kepler field
• Towards Accurate Asteroseismic Masses for Luminous Giants
• Hidden oscillations in plain sight: identification of seismically unresolved red-giant asteroseismic binary candidates
• A 'Quick Look' at All-Sky Galactic Archeology with TESS: 158,000 Oscillating Red Giants from the MIT Quick-Look Pipeline