2005/04/05 by P. ReFiorentin, A. Helmi, ReFiorentin, P. +5
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0504109
9 pages, 6 figures, accepted for publication in A&A
arxiv created 2005/04/05 · openalex publication_date 2005/04/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have analyzed the catalog of 2106 non-kinematically selected metal poor stars in the solar neighborhood published by Beers et al. (2000), with the goal of quantifying the amount of substructure in the motions of the fastest halo stars. We have computed the two-point velocity correlation function for a subsample of halo stars within 1-2 kpc of the Sun, and found statistical evidence of substructure, with a similar amplitude to that predicted by high resolution CDM simulations. The signal is due to a small kinematic group whose dynamical properties are compared to the stellar "stream", previously discovered by Helmi et al. (1999). If real, this high velocity moving group would provide further support to the idea that substructures remain as fossils from the formation of the Galaxy as expected in the CDM scenario.