English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Recent observational studies have uncovered a small number of very metal-poorstars with cold kinematics in the Galactic disc and bulge. However, theirorigins remain enigmatic. We select a total of 138 Milky Way (MW) analogs fromthe TNG50 cosmological simulation based on their $z=0$ properties: diskymorphology, stellar mass, and local environment. In order to make morepredictive statements for the MW, we further limit the spatial volume coverageof stellar populations in galaxies to that targeted by the upcoming 4MOSThigh-resolution survey of the Galactic disc and bulge. We find that across allgalaxies, $\sim$20 per cent of very metal-poor (${\rm [Fe/H]} < -2$) starsbelong to the disk, with some analogs reaching 30 per cent. About 50$\pm$10 percent of the VMP disc stars are, on average, older than 12.5 Gyr and$\sim$70$\pm$10 per cent come from accreted satellites. A large fraction of theVMP stars belong to the halo ($\sim$70) and have a median age of 12 Gyr. Ourresults with the TNG50 cosmological simulation confirm earlier findings withsimulations of fewer individual galaxies, and suggest that the stellar disc ofthe Milky Way is very likely to host significant amounts of very- andextremely-metal-poor stars that, although mostly of ex situ origin, can alsoform in situ, reinforcing the idea of the existence of a primordial Galacticdisc.

On the likelihoods of finding very metal-poor (and old) stars in the Milky Way's disc, bulge, and halo