Current Challenges in Cepheid Distance Calibrations Using Gaia EDR3

Abstract

Using parallaxes from Gaia Early Data Release 3 (EDR3), we determine multi-wavelength BVI, JHK, and [3.6] & [4.5] micron absolute magnitudes for 37 nearby Milky Way Cepheids, covering the period range between 5 and 60 days. We apply these period-luminosity relations to Cepheids in the Large and Small Magellanic Clouds, and find that the derived distances are significantly discrepant with the geometric distances according to detached eclipsing binaries (DEBs). We explore several potential causes of these issues, including reddening, metallicity, and the existence of an additional zero-point offset, but none provide a sufficient reconciliation with both DEB distances. We conclude that the combination of the systematic uncertainties on the EDR3 parallaxes with the uncertainties on the effect of metallicity on the Cepheid distance scale leads to a systematic error floor of approximately 3%. We therefore find that the EDR3 data is not sufficiently accurate in the regime of these bright Cepheids to determine extragalactic distances precise to the 1% level at this time, in agreement with a number of contemporary studies.

23 pages, 9 figures, 11 tables. Accepted for publication in ApJ

References in corpus (16)

• The NumPy array: a structure for efficient numerical computation
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• Cosmic Distances Calibrated to 1% Precision with Gaia EDR3 Parallaxes and Hubble Space Telescope Photometry of 75 Milky Way Cepheids Confirm Tension with LambdaCDM
• A distance to the Large Magellanic Cloud that is precise to one per cent
• A million binaries from Gaia eDR3: sample selection and validation of Gaia parallax uncertainties
• A new Cepheid distance to the maser-host galaxy NGC 4258 and its implications for the Hubble Constant
• Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
• The influence of chemical composition on the properties of Cepheid stars. II-The iron content
• A new calibration of Galactic Cepheid Period-Luminosity relations from B to K bands, and a comparison to LMC PL relations
• Cepheid Parallaxes and the Hubble Constant
• Period-Luminosity Relations Derived from the OGLE-III Fundamental Mode Cepheids
• The Parallax Zero-Point of Gaia Early Data Release 3 from LAMOST Primary Red Clump Stars
• Cepheid Metallicity in the Leavitt Law (C-MetaLL) survey: I. HARPS-N@TNG spectroscopy of 47 Classical Cepheid and 1 BL Her variables
• Distance Dependent Offsets between Parallaxes for Nearby Stars and Gaia DR1 Parallaxes