Infrared Surface Brightness Distances to Cepheids: a comparison of Bayesian and linear-bisector calculations

Abstract

We have compared the results of Bayesian statistical calculations and linear-bisector calculations for obtaining Cepheid distances and radii by the infrared surface brightness method. We analyzed a set of 38 Cepheids using a Bayesian Markov Chain Monte Carlo method that had been recently studied with a linear-bisector method. The distances obtained by the two techniques agree to 1.5 \pm 0.6% with the Bayesian distances being larger. The radii agree to 1.1% \pm 0.7% with the Bayesian determinations again being larger. We interpret this result as demonstrating that the two methods yield the same distances and radii. This implies that the short distance to the LMC found in recent linear-bisector studies of Cepheids is not caused by deficiencies in the mathematical treatment. However, the computed uncertainties in distance and radius for our dataset are larger in the Bayesian calculation by factors of 1.4-6.7. We give reasons to favor the Bayesian computations of the uncertainties. The larger uncertainties can have a significant impact upon interpretation of Cepheid distances and radii obtained from the infrared surface brightness method.

arXiv comment27 pages with 9 figures

References in corpus (7)

• The effect of metallicity on the Cepheid Period-Luminosity relation from a Baade-Wesselink analysis of Cepheids in the Galaxy and in the Small Magellanic Cloud
• Direct Distances to Cepheids in the Large Magellanic Cloud: Evidence for a Universal Slope of the Period-Luminosity Relation up to Solar Abundance
• Very accurate Distances and Radii of Open Cluster Cepheids from a Near-Infrared Surface Brightness Technique
• Calibration of the Distance Scale from Cepheids
• A Near-Infrared Variant of the Barnes-Evans Method For Finding Cepheid Distances Calibrated with High-Precision Angular Diameters
• Calibration of the Barnes-Evans relation using interferometric observations of Cepheids
• A Bayesian Analysis of the Cepheid Distance Scale

Cited by in corpus (14)

• A new calibration of Galactic Cepheid Period-Luminosity relations from B to K bands, and a comparison to LMC PL relations
• Calibrating the Cepheid Period-Luminosity relation from the infrared surface brightness technique I. The p-factor, the Milky Way relations, and a universal K-band relation
• Calibrating the Cepheid Period-Luminosity relation from the infrared surface brightness technique II. The effect of metallicity, and the distance to the LMC
• Baade-Wesselink distances to Galactic and Magellanic Cloud Cepheids and the effect of metallicity
• Galactic Cepheids with Spitzer: I. Leavitt Law and Colors
• The effect of metallicity on Cepheid Period-Luminosity relations from a Baade-Wesselink analysis of Cepheids in the Milky Way and Magellanic Clouds
• Extended envelopes around Galactic Cepheids III. Y Oph and alpha Per from near-infrared interferometry with CHARA/FLUOR
• Baade-Wesselink distances and the effect of metallicity in classical cepheids
• The long-period Galactic Cepheid RS Puppis - I. A geometric distance from its light echoes
• CORS Baade-Wesselink method in the Walraven photometric system: the Period-Radius and the Period-Luminosity relation of Classical Cepheids
• Calibrating the projection factor for Galactic Cepheids
• The long-period Galactic Cepheid RS Puppis - III. A geometric distance from HST polarimetric imaging of its light echoes
• Observations of the pulsation of the Cepheid l Car with the Sydney University Stellar Interferometer
• HARPS-N high spectral resolution observations of Cepheids II. The impact of the surface-brightness color relation on the Baade-Wesselink projection factor of eta Aql