Comparison of the Asteroseismic Mass Scale of Red Clump Giants with Photometric Mass Estimates

Abstract

Asteroseismology can provide joint constraints on masses and radii of individual stars. While this approach has been extensively tested for red giant branch (RGB) stars, it has been more difficult to test for helium core-burning red-clump (RC) giants because of the lack of fundamental calibrators. To provide independent mass estimates, we utilize a number of widely used horizontal-branch (HB) models in the literature, and derive photometric masses from a comparison with $griBV{I}_{C}JH{K}_s$ photometry. Our selected models disagree with each other on the predicted mass-luminosity-temperature relation. We adopt first-order corrections on colors and magnitudes to minimize the dispersion between different models by forcing models to match the observed location in the solar-metallicity cluster M67. Even for these calibrated models, however, the internal consistency between models deteriorates at higher metallicities, and photometric masses become smaller than asteroseismic masses, as seen from metal-rich field RC stars with Gaia parallaxes. Similarly, the average photometric mass for metal-rich NGC 6791 stars ranges from $0.7M_{\odot }$ to $1.1M_{\odot }$, depending on the specific set of models employed. An ensemble average of the photometric masses ($0.88\pm 0.16M_{\odot }$) in NGC 6791 is marginally consistent with the asteroseismic mass ($1.16\pm 0.04M_{\odot }$). There is a clear tension between the masses that one would predict from photometry for metal-rich field RC stars, asteroseismic masses, and those that would be expected from the ages of stars in the Galactic disk populations and canonical RGB mass loss. We conclude that standard RC models need to be re-examined in light of these powerful new data sets.

30 pages, 20 figures, 6 tables, accepted for publication in the Astrophysical Journal after minor revision

References in corpus (34)

• The Gaia mission
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The Dartmouth Stellar Evolution Database
• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• Scaled solar tracks and isochrones in a large region of the Z-Y plane I. From the ZAMS to the TP-AGB end for 0.15 - 2.5 Mo stars
• A new implementation of the infrared flux method using the 2MASS catalogue
• The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
• The SEGUE Stellar Parameter Pipeline. II. Validation with Galactic Globular and Open Clusters
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• Synthetic Stellar Photometry - I. General considerations and new transformations for broad-band systems
• The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass
• The Distances to Open Clusters from Main-Sequence Fitting. III. Improved Accuracy with Empirically Calibrated Isochrones
• Mass loss on the red giant branch: the value and metallicity dependence of Reimers' η in globular clusters
• Galactic Globular and Open Clusters in the Sloan Digital Sky Survey. II. Test of Theoretical Stellar Isochrones
• A new abundance scale for the globular cluster 47 Tuc
• The red clump absolute magnitude based on revised Hipparcos parallaxes
• The First Empirical Mass Loss Law for Population II Giants
• Empirical photometric calibration of the Gaia Red Clump: colours, effective temperature and absolute magnitude
• Changing the ${\nu }_{\max }$ Scaling Relation: The Need For a Mean Molecular Weight Term
• The K2 M67 Study: Revisiting old friends with K2 reveals oscillating red giants in the open cluster M67
• The Distances to Open Clusters from Main-Sequence Fitting. IV. Galactic Cepheids, the LMC, and the Local Distance Scale
• Sodium and Oxygen Abundances in the Open Cluster NGC 6791 from APOGEE H-Band Spectroscopy
• Red clump stars and Gaia: Calibration of the standard candle using a hierarchical probabilistic model
• Searching for Chemical Signatures of Multiple Stellar Populations in the Old, Massive Open Cluster NGC 6791
• A New Look at the Old Star Cluster NGC 6791
• Fiducial Stellar Population Sequences for the u'g'r'i'z' System
• The end of the white dwarf cooling sequence in M 67
• vbyCaHbeta CCD Photometry of Clusters. VIII. The Super-Metal Rich, Old Open Cluster NGC 6791
• WIYN Open Cluster Study. LIX. Radial-Velocity Membership of the Evolved Population of the Old Open Cluster NGC 6791
• Spitzer Space Telescope evidence in NGC 6791: no super-mass-loss at super-solar metallicity to explain helium white dwarfs?
• A new search for planet transits in NGC 6791
• The Helium Abundance of NGC 6791 from Modeling of Stellar Oscillations
• The Old, Super-Metal-Rich Open Cluster, NGC 6791 - Elemental Abundances in Turn-off Stars from Keck/HIRES Spectra
• Uncertainties in stellar evolution models: convective overshoot

Cited by in corpus (13)

• Testing the radius scaling relation with $Gaia$ DR2 in the $Kepler$ field
• Discovery of post-mass-transfer helium-burning red giants using asteroseismology
• The K2 Galactic Archaeology Program Data Release 3: Age-abundance patterns in C1-C8 and C10-C18
• TESS Asteroseismology of the known red-giant host stars HD 212771 and HD 203949
• 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
• The APO-K2 Catalog. II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way
• A Blueprint for the Milky Way's Stellar Populations. II. Improved Isochrone Calibration in the SDSS and Pan-STARRS Photometric Systems
• Asteroseismic Study of Subgiants and Giants of the Open Cluster M67 using Kepler/K2: Expanded Sample and Precise Masses
• A Blueprint for the Milky Way's Stellar Populations. IV. A String of Pearls $-$ the Galactic Starburst Sequence
• A Blueprint for the Milky Way's Stellar Populations. V. 3D Local Dust Extinction
• Open cluster age calibration from colour-magnitude morphological indices using Gaia DR3 data
• On the Age Calibration of Open Clusters using Red Clump Stars