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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Super-metal-rich (SMR) stars, currently in the solar neighbourhood, areexpected to originate only in the inner Galaxy and have definitely migrated. Weaim at studying a large sample of SMR stars to provide constraints on the epochof the bar formation and its impact on the MW disc stellar populations. Weinvestigate a sample of 169,701 MSTO and SGB stars with 6D phase spaceinformation and high-quality stellar parameters coming from the hybrid-CNNanalysis of the Gaia-DR3 RVS stars. We compute distances and ages using theStarHorse code with a mean precision of 1% and 11%, respectively. From these,11,848 stars have metallicity ([Fe/H]) above 0.15 dex. We report a metallicitydependence of spatial distribution of stellar orbits shown by the bimodaldistribution in the guiding radius at 6.9 and 7.9 kpc, first appearing at[Fe/H]~0.1 dex, becoming very pronounced at larger [Fe/H]. In addition, we'veobserved a trend where the most metal-rich stars, with [Fe/H]~0.4 dex, arepredominantly old (9-12 Gyrs) but show a gradual decline in [Fe/H] with age,reaching around 0.25 dex at about 4 Gyrs ago, followed by a sharp drop around 3Gyrs ago. Furthermore, our full dataset reveals a clear peak in theage-metallicity relationship during the same period, indicating a SF burstaround 3-4 Gyrs ago with slightly sub-solar [Fe/H] and enhanced [$\alpha$/Fe].We show the SMR stars are good tracers of the bar activity. We interpret thesteep decrease in number of SMR stars at around 3 Gyr as the end of the barformation epoch. In this scenario, the peak of bar activity also coincides witha peak in the SF activity in the disc. Although the SF burst around 3 Gyr agohas been reported previously, its origin was unclear. Here, we suggest the SFburst to have been triggered by the high bar activity, 3-4 Gyr ago. Accordingto these results and interpretation, the MW bar could be young.

Insights from Super-Metal-Rich Stars: Is the Milky Way bar young?