2003/07/02 by Ortwin Gerhard, Gerhard, Ortwin · 2 citations
Chemistry · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Spectroscopy and Laser Applications #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0307057
Invited talk, 8 pages, LaTeX, 2 figures. To appear in New Horizons in Globular Cluster Astronomy, Padova 2002, ASP Conf. Proc., eds. G. Piotto, G. Meylan, G. Djorgowski, M. Riello
arxiv created 2003/07/02 · openalex publication_date 2003/07/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recent observational and theoretical work suggests that the formation of the Galactic stellar halo involved both dissipative processes and the accretion of subfragments. With present data, the fraction of the halo for which an accretion origin can be substantiated is small, of order 10 percent. The kinematics of the best halo field star samples show evidence for both dissipative and dissipationless formation processes. Models of star-forming dissipative collapse, in a cosmological context and including feedback from star formation, do not confirm the simple relations between metallicity, rotation velocity, and orbital eccentricity for halo stars as originally predicted. The new model predictions are much closer to the observed distributions, which have generally been interpreted as evidence for an accretion origin. These results are broadly consistent with a hierarchical galaxy formation model, but the details remain to be worked out.