The Gaia-ESO Survey: a quiescent Milky Way with no significant dark/stellar accreted disc

Summary, in English

According to our current cosmological model, galaxies like the Milky Way are expected to experience many mergers over their lifetimes. The most massive of the merging galaxies will be dragged towards the disc plane, depositing stars and dark matter into an accreted disc structure. In this work, we utilize the chemodynamical template developed in Ruchti et al. to hunt for accreted stars. We apply the template to a sample of 4675 stars in the third internal data release from the Gaia-ESO Spectroscopic Survey. We find a significant component of accreted halo stars, but find no evidence of an accreted disc component. This suggests that the Milky Way has had a rather quiescent merger history since its disc formed some 8-10 billion years ago and therefore possesses no significant dark matter disc.

• Författare: Gregory Ruchti; J. I. Read; Sofia Feltzing; A. M. Serenelli; Paul McMillan; K. Lind; Thomas Bensby; M. Bergemann; M. Asplund; A. Vallenari; E. Flaccomio; E. Pancino; A. J. Korn; A. Recio-Blanco; A. Bayo; G. Carraro; M. T. Costado; F. Damiani; U. Heiter; A. Hourihane; P. Jofre; G. Kordopatis; C. Lardo; P. de Laverny; L. Monaco; L. Morbidelli; L. Sbordone; C. C. Worley; S. Zaggia
• Avdelning/ar: Astronomi - Har omorganiserats
• Publiceringsår: 2015
• Språk: Engelska
• Sidor: 2874-2887
• Publikation/Tidskrift/Serie: Monthly Notices of the Royal Astronomical Society
• Volym: 450
• Issue: 3
• Länkar: http://dx.doi.org/10.1093/mnras/stv807
• Dokumenttyp: Artikel i tidskrift
• Förlag: Oxford University Press
• Ämne: Astronomy, Astrophysics and Cosmology
• Nyckelord: surveys; stars: abundances; stars: kinematics and dynamics; Galaxy:; disc; Galaxy: evolution; Galaxy: formation
• Status: Published
• Projekt: Gaia-ESO Survey
• ISBN/ISSN/Övrigt: ISSN: 1365-2966