Analysis of Peculiarities of the Stellar Velocity Field in the Solar Neighborhood

TL;DR

This study analyzes the stellar velocity field in the solar neighborhood using updated catalogs, identifying known streams, confirming the KFR08 stream, and exploring their ages and metallicities to understand their origins.

Contribution

It provides a detailed analysis of stellar velocity streams with new data, confirming the KFR08 stream and estimating ages, offering insights into their common origins.

Findings

Confirmed the existence of the KFR08 stream.

Estimated the age of KFR08 stream as 13 Gyr.

Found similar ages and metallicities for Wolf 630-alpha Ceti and Hercules streams.

Abstract

Based on a new version of the Hipparcos catalogue and an updated Geneva-Copenhagen survey of F and G dwarfs, we analyze the space velocity field of about 17000 single stars in the solar neighborhood. The main known clumps, streams, and branches (Pleiades, Hyades, Sirius, Coma Berenices, Hercules, Wolf 630-alpha Ceti, and Arcturus) have been identified using various approaches. The evolution of the space velocity field for F and G dwarfs has been traced as a function of the stellar age. We have managed to confirm the existence of the recently discovered KFR08 stream. We have found 19 Hipparcos stars, candidates for membership in the KFR08 stream, and obtained an isochrone age estimate for the stream, 13 Gyr. The mean stellar ages of the Wolf 630-alpha Ceti and Hercules streams are shown to be comparable, 4--6 Gyr. No significant differences in the metallicities of stars belonging to these streams have been found. This is an argument for the hypothesis that these streams owe their origin to a common mechanism.