Recent versions of the observed cosmic star-formation history ( SFH ) have resolved an inconsistency with the stellar mass density history .
We show that the revised SFH also scales up the delay-time distribution ( DTD ) of Type Ia supernovae ( SNe Ia ) , as determined from the observed volumetric SN Ia rate history , aligning it with other field-galaxy SN Ia DTD measurements .
The revised-SFH-based DTD has a t ^ { -1.1 \pm 0.1 } form and a Hubble-time-integrated production efficiency of N / M _ { \star } = 1.3 \pm 0.1 SNe Ia per 1000 ~ { } { M _ { \odot } } of formed stellar mass .
Using these revised histories and updated empirical iron yields of the various SN types , we re-derive the cosmic iron accumulation history .
Core-collapse SNe and SNe Ia have contributed about equally to the total mass of iron in the Universe today .
We find the track of the average cosmic gas element in the [ \alpha /Fe ] vs. [ Fe/H ] abundance-ratio plane .
The track is broadly similar to the observed main locus of Galactic stars in this plane , indicating a Milky Way ( MW ) SFH similar in form to the cosmic one .
We easily find a simple MW SFH that makes the track closely match this stellar locus .
Galaxy clusters appear to have a higher-normalization DTD .
This cluster DTD , combined with a short-burst MW SFH peaked at z = 3 , produces a track that matches remarkably well the observed “ high- \alpha ” locus of MW stars , suggesting the halo/thick-disk population has had a galaxy-cluster-like formation mode .
Thus , a simple two-component SFH , combined with empirical DTDs and SN iron yields , suffices to closely reproduce the MW ’ s stellar abundance patterns .