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

Journal
Date Issued
2015
Author(s)
Ruchti, G. R.
•
Read, J. I.
•
Feltzing, S.
•
Serenelli, A. M.
•
McMillan, P.
•
Lind, K.
•
Bensby, T.
•
Bergemann, M.
•
Asplund, M.
•
•
•
•
Korn, A. J.
•
Recio-Blanco, A.
•
Bayo, A.
•
Carraro, G.
•
Costado, M. T.
•
•
Heiter, U.
•
Hourihane, A.
•
Jofré, P.
•
Kordopatis, G.
•
Lardo, C.
•
de Laverny, P.
•
Monaco, L.
•
•
Sbordone, L.
•
Worley, C. C.
•
DOI
Description
GRR, SF, and TB acknowledge support from the project grant ‘The New Milky Way’ from the Knut and Alice Wallenberg Foundation. JIR would like to acknowledge support from SNF grant PP00P2_128540/1. This work was partially supported by grants ESP2013-41268-R (MINECO) and 2014SGR-1458 (Generalitat of Catalunya). KL acknowledges support from the European Union FP7-PEOPLE-2012-IEF grant no. 328098. UH acknowledges support from the Swedish National Space Board (SNSB/Rymdstyrelsen). LS acknowledges the support of Chile's Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS. This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and Ministero dell’ Istruzione, dell’ Università’ e della Ricerca (MIUR) in the form of the grant ‘Premiale VLT 2012’. The results presented here benefit from discussions held during the Gaia -ESO workshops and conferences supported by the ESF (European Science Foundation) through the GREAT Research Network Programme.
Abstract
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.
Volume
450
Issue
3
Start page
2874
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2015MNRAS.450.2874R
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

stv807.pdf

Size

2.92 MB

Format

Adobe PDF

Checksum (MD5)

c7e343663c313acab116c1d662877087