Analysis of the Distance Scales by Cepheids from the Gaia EDR3 Catalogue Data

TL;DR

This study compares Cepheid-based distance estimates from Gaia EDR3 data, revealing a 10% need to lengthen the Skowron et al. scale, and refines Galactic rotation and spiral wave parameters.

Contribution

It introduces a method comparing derivatives of Galactic rotation velocity to calibrate Cepheid distance scales using Gaia data.

Findings

Distance scale from Skowron et al. should be increased by about 10%.

Confirmed the scale correction through comparison with Gaia parallaxes.

Provided updated Galactic rotation and spiral density wave parameters.

Abstract

We study the kinematics of a sample of classical Cepheids younger than 120 Myr. For these stars, the estimates of distances taken from Skowron et al., which are based on the period-luminosity relation, and the line-of-sight velocities and the proper motions from the Gaia catalog are available. There are also distance estimates derived from the trigonometric parallaxes contained in the Gaia ERD3 catalog. A method, which relies on comparison of the first-order derivative of the Galactic rotation angular velocity, showed the need to lengthen the distance scales determined by Skowron et al. by about 10%. This conclusion was confirmed by direct comparison to the distances predicted on using the trigonometric parallaxes. With taking into account this result, we obtained new estimates of the Galactic rotation parameters and the parameters of a spiral density wave.