New and Known Moving Groups And Clusters Identified in a Gaia Co-Moving Catalog

TL;DR

This paper reorganizes a large catalog of star groups from Gaia data, identifying new and known co-moving stellar groups, and provides insights into their ages, compositions, and memberships, enhancing understanding of stellar associations in the Milky Way.

Contribution

It introduces a re-organization of the Oh17 catalog into new and known groups, identifying 6 new groups and expanding membership details using multi-survey data and kinematic analysis.

Findings

Identified 6 new stellar groups older than Pleiades but younger than 1 Gyr.

Discovered 400 new members across 20 associations requiring further validation.

Most groups contain solar-type stars with solar metallicity.

Abstract

We present a re-organization of the Oh et al. (2017b) (Oh17) wide, co-moving catalog of 4,555 groups of stars (10,606 individual objects) identified in the Tycho Gaia Astrometric Survey (TGAS) into new and known co evolving groups of stars in the Milky Way. We use the BANYAN {\Sigma} kinematic analysis tool to identify 1,015 individual stars in the Oh17 catalog that yielded a >80% probability in one of 27 known associations (e.g. the AB Doradus moving group, Columba, Upper Scorpius) in the vicinity of the Sun. Among the 27 groups uncovered by Oh17 that had > 10 connected components, we find that 6 are newly discovered. We use a combination of Tycho, Gaia, 2MASS, WISE, Galex, and ROSAT photometry as well as Gaia parallaxes to determine that these new groups are likely older than the Pleiades but younger than ~1 Gyr. Using isochrone fitting we find that the majority of these new groups have solar type stars and solar type metallicity. Among the 35 Oh17 groups with 5 - 9 members, we find that 19 also appear new and co-moving, with one group well within 100pc (range of 77 - 90 pc). For known star forming regions, open clusters, and moving groups identified by Oh17, we find that the majority were broken up into pieces over several Oh17 groups (e.g. Lower Centaurus Crux members are spread over 26 Oh17 groups) however we found no correlation with positions of the groups on color magnitude diagrams therefore no substructure of the association correlated with the Oh17 designated group. We find that across the 27 groups tested by BANYAN {\Sigma} there were 400 new members to 20 different associations uncovered by Oh17 that require further vetting.