The Milky Way has no in-situ halo but it has a thick disc. Composition of the stellar halo and age-dating the last significant merger with Gaia DR2 and APOGEE
Preprint published in 2018 by
P. Di Matteo,
M. Haywood,
M. D. Lehnert 
,
D. Katz,
S. Khoperskov,
O. N. Snaith,
A. Gómez,
N. Robichon
,
D. Katz,
S. Khoperskov,
O. N. Snaith,
A. Gómez,
N. Robichon
