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

We investigate the contribution of sub-Chandrasekhar mass Type Ia supernovaeto the chemical enrichment of the Gaia Sausage galaxy, the progenitor of asignificant merger event in the early life of the Milky Way. Using acombination of data from Nissen & Schuster (2010), the 3rd GALAH data release(with 1D NLTE abundance corrections) and APOGEE data release 16, we fitanalytic chemical evolution models to a 9-dimensional chemical abundance space(Fe, Mg, Si, Ca, Cr, Mn, Ni, Cu, Zn) in particular focusing on the iron-peakelements, Mn and Ni. We find that low [Mn/Fe] $\sim-0.15\,\mathrm{dex}$ and low[Ni/Fe] $\sim-0.3\,\mathrm{dex}$ Type Ia yields are required to explain theobserved trends beyond the [$\alpha$/Fe] knee of the Gaia Sausage(approximately at [Fe/H] $=-1.4\,\mathrm{dex}$). Comparison to theoreticalyield calculations indicate a significant contribution from sub-Chandrasekharmass Type Ia supernovae in this system (from $\sim60$% to $100$% depending onthe theoretical model with an additional $\pm10$% systematic from NLTEcorrections). We compare to results from other Local Group environmentsincluding dwarf spheroidal galaxies, the Magellanic Clouds and the Milky Way'sbulge, finding the Type Ia [Mn/Fe] yield must be metallicity-dependent. Ourresults suggest that sub-Chandrasekhar mass channels are a significant, perhapseven dominant, contribution to Type Ia supernovae in metal-poor systems, whilstmore metal-rich systems could be explained by metallicity-dependentsub-Chandrasekhar mass yields, possibly with additional progenitor massvariation related to star formation history, or an increased contribution fromChandrasekhar mass channels at higher metallicity.

Evidence for sub-Chandrasekhar Type Ia supernovae from the last major merger