Tracing the structure of the Milky Way with detached eclipsing binaries from the VVV survey - I. The method and initial results

Abstract

We present the first results of a project aiming to trace the spatial structure of the Milky Way using detached eclipsing binaries (DEBs) as distance indicators. A sample of DEBs from the OGLE-II catalogue was selected and their near infrared photometry was taken from the Vista Variables in the Via Lactea (VVV) survey. The I band OGLE-II light curves are used to create models of the DEBs, which together with the VVV photometry are compared with a set of theoretical isochrones. After correcting for stellar reddening, we find a set of absolute physical parameters of components of a given binary, including absolute magnitudes and distances. With this approach we can calculate the distances with the precision better than 5 per cent. Even though we have a few systems, the distribution is not homogeneous along the line of sight, and appears to follow the overall structure of the Galaxy - several spiral arms and the Bulge are distinguishable. A number of systems can be seen behind the Bulge, reaching even the distance to the Sagittarius dwarf galaxy.

15 pages, 4+2 figures, 5 tables, accepted by MNRAS

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Cited by in corpus (7)

• The VVV Templates Project. Towards an Automated Classification of VVV Light-Curves. I. Building a database of stellar variability in the near-infrared
• The VVV Infrared Variability Catalog (VIVA-I)
• Unveiling short period binaries in the inner VVV bulge
• Automated classification of eclipsing binary systems in the VVV Survey
• Photometric study of the SMCNOD using variable stars from the OGLE-IV survey
• The First Eclipsing Binary Catalogue from the MOA-II database
• A hundred new eclipsing binary system candidates studied in a near-infrared window in the VVV survey