Validation of the Gaia Early Data Release 3 parallax zero-point model with asteroseismology

Abstract

The Gaia Early Data Release 3 (EDR3) provides trigonometric parallaxes for 1.5 billion stars, with reduced systematics compared to Gaia Data Release 2 and reported precisions better by up to a factor of two. New to EDR3 is a tentative model for correcting the parallaxes of magnitude-, position-, and color-dependent systematics for five- and six-parameter astrometric solutions, $Z_5$ and $Z_6$. Using a sample of over 2,000 first-ascent red giant branch stars with asteroseismic parallaxes, I perform an independent check of the $Z_5$ model in a Gaia magnitude range of $9\lesssim G\lesssim 13$ and color range of $1.4\mu {\mathrm{m}}^{-1}\lesssim {\nu }_{\mathrm{eff}}\lesssim 1.5\mu {\mathrm{m}}^{-1}$. This analysis therefore bridges the Gaia team's consistency check of $Z_5$ for $G>13$, and indications from independent analysis using Cepheids of a $\approx 15\mu \mathrm{as}$ over-correction for $G<11$. I find an over-correction sets in at $G\lesssim 10.8$, such that $Z_5$-corrected EDR3 parallaxes are larger than asteroseismic parallaxes by $15\pm 3\mu \mathrm{as}$. For $G\gtrsim 10.8$, EDR3 and asteroseismic parallaxes in the Kepler field agree up to a constant consistent with expected spatial variations in EDR3 parallaxes after a linear, color-dependent adjustment. I also infer an average under-estimation of EDR3 parallax uncertainties in the sample of $22\pm 6\%$, consistent with the Gaia team's estimates at similar magnitudes and independent analysis using wide binaries. Finally, I extend the Gaia team's parallax spatial covariance model to brighter magnitudes ($G<13$) and smaller scales (down to $\approx 0.1°$), where systematic EDR3 parallax uncertainties are at least $\approx 3-4\mu \mathrm{as}$.

Published in AJ

References in corpus (28)

• The NumPy array: a structure for efficient numerical computation
• Modules for Experiments in Stellar Astrophysics (MESA)
• The 2.5 m Telescope of the Sloan Digital Sky Survey
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Cosmic Distances Calibrated to 1% Precision with Gaia EDR3 Parallaxes and Hubble Space Telescope Photometry of 75 Milky Way Cepheids Confirm Tension with LambdaCDM
• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• A new implementation of the infrared flux method using the 2MASS catalogue
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
• Asteroseismology and Gaia: Testing Scaling Relations Using 2200 Kepler Stars with TGAS Parallaxes
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• Distances and parallax bias in Gaia DR2
• A new standard: Age and distance for the open cluster NGC 6791 from the eclipsing binary member V20
• Testing the radius scaling relation with $Gaia$ DR2 in the $Kepler$ field
• Challenges for asteroseismic analysis of Sun-like stars
• The Parallax Zero-Point of Gaia Early Data Release 3 from LAMOST Primary Red Clump Stars
• Testing asteroseismology with Gaia DR2: Hierarchical models of the Red Clump
• RR Lyrae variables in Messier 53: Near-infrared Period--Luminosity relations and the calibration using Gaia Early Data Release 3
• Asteroseismic versus Gaia distances: a first comparison
• Using red clump stars to correct the Gaia DR1 parallaxes
• Distance Dependent Offsets between Parallaxes for Nearby Stars and Gaia DR1 Parallaxes
• Testing the intrinsic scatter of the asteroseismic scaling relations with Kepler red giants
• Evidence for spatially-correlated $Gaia$ parallax errors in the $Kepler$ field
• Kinematics and Multi Band Period-Luminosity-Metallicity Relation of RR Lyrae Stars via Statistical Parallax
• A theoretical scenario for Galactic RR Lyrae in the Gaia database: constraints on the parallax offset
• Distance scale for high-luminosity stars in OB associations and in field with Gaia DR2. Spurious systematic motions
• Mapping Gaia parallax systematic errors over the sky with faint Milky Way stars
• Parameters of the Link between the Optical and Radio Frames from Gaia DR2 Data and VLBI Measurements