Search for Stellar Streams in The Galactic Halo From Gaia DR2, GALAH DR2, RAVE DR5 and LAMOST DR4 Data

Abstract

Stellar streams are stars which are trapped in the same potensial caused by dynamical resonance or tidal force. We aim to analyze kinematic sub- structures (streams) in the Galactic halo by V vs √ U2+ 2V 2 planes of Arifyanto & Fuchs. We crossmatched data from Gaia DR2, GALAH DR2, RAVE DR5 and LAMOST DR4 based on positions. We have 3D kinematics and metallicity data of halo stars selected from kinematics criteria from ratio of probability of thick disk (TD) over halo (H) less than 0.01. Substructures are detected by using wavelet transformation and corrected using 15 Monte Carlo simulations. We obtained four kinematic structures on V vs √U2 + 2V 2 plane which two of them are associated to BB17-1 and BB17-2 streams. All the streams had a high probability from the extragalactic origin.