Kinematic groups beyond the Solar neighbourhood with RAVE

TL;DR

This study maps and analyzes the large-scale kinematic groups of disc stars beyond the Solar neighborhood using RAVE survey data, revealing their spatial extent, shifts, and potential links to Galactic dynamics.

Contribution

It extends the understanding of stellar kinematic groups beyond the Solar neighborhood and identifies new features and shifts linked to Galactic structures.

Findings

Local kinematic groups are large-scale features surviving up to 1 kpc from the Sun.

Known groups shift in velocity space at different Galactic radii.

A new kinematic group was discovered at (U, V) = (92, -22) km/s.

Abstract

We analyse the kinematics of disc stars observed by the RAVE survey in and beyond the Solar neighbourhood.We detect significant overdensities in the velocity distributions using a technique based on the wavelet transform.We find that the main local kinematic groups are large scale features, surviving at least up to ~1 kpc from the Sun in the direction of anti-rotation, and also at ~700 pc below the Galactic plane.We also find that for regions located at different radii than the Sun, the known groups appear shifted in the velocity plane. For example, the Hercules group has a larger azimuthal velocity for regions inside the Solar circle and a lower value outside. We have also discovered a new group at (U, V) = (92,-22) km/s in the Solar neighbourhood and confirmed the significance of other previously found groups. Some of these trends detected for the first time are consistent with dynamical models of the effects of the bar and the spiral arms. More modelling is required to definitively characterise the non-axisymmetric components of our Galaxy using these groups.