New distance and depth estimates from observations of eclipsing binaries in the SMC

TL;DR

This study uses observations of eclipsing binaries in the SMC to accurately determine stellar parameters and the galaxy's distance, revealing its depth and kinematic properties.

Contribution

It provides new distance and depth estimates for the SMC using a sample of eclipsing binaries with combined radial velocity and light curve data.

Findings

Mean distance modulus of 19.05 for the SMC

SMC depth of approximately 10.6 kpc

Insights into the kinematics of binary stars and H II gas

Abstract

A sample of 33 eclipsing binaries observed in a field of the SMC with FLAMES@VLT is presented. The radial velocity curves obtained, together with existing OGLE light curves, allowed the determination of all stellar and orbital parameters of these binary systems. The mean distance modulus of the observed part of the SMC is 19.05, based on the 26 most reliable systems. Assuming an average error of 0.1 mag on the distance modulus to an individual system, and a gaussian distribution of the distance moduli, we obtain a 2-sigma depth of 0.36 mag or 10.6 kpc. Some results on the kinematics of the binary stars and of the H II gas are also given.