A Test of the Supernova Trigger Hypothesis with ^(60)Fe and ^(26)Al

Abstract

It is shown that if the ^(26)Al inventory of the early solar system, taken as (^(26)Al/^(27)Al)_☉ = 5×10^(−5), is a result of injection of fresh debris from a Type II supernova (SNII), then ^(60)Fe/^(56)Fe would have to be between 3×10^(−7) and 1×10^(−5). This inferred correlation of ^(26)Al and ^(60)Fe is based on the observation that both nuclei are produced dominantly in the O/Ne zone and that for SNII ejecta ^(26)Al/^(60)Fe is between 0.6 and 23. A similar correlation applies to ^(41)Ca,^(36)Cl,^(16)O, and ^(18)O, which are also produced in the same zone or in nearby regions. The supernova trigger hypothesis may be tested by determination of ^(60)Ni excesses correlated with Fe in samples where ^(26)Al was demonstrated to be present. From available experimental data, it appears that the observed abundance of ^(60)Fe is too low to be compatible with a supernova trigger that injected the ^(26)Al into the protosolar nebula. The same is true for ^(53)Mn, a short-lived nucleus produced in the outer edge of the Ni core.