Supernova-produced 53Mn on Earth

GUNTHER KORSCHINEK; THOMAS FAESTERMANN ; MIKHAIL POUTIVTSEV; ANDRES ARAZI; KLAUS KNIE; GEORG RUGEL; ANTON WALLNER

Hannover

Encuentro; Tagung der Deutsche Physikalische Gesellschaft; 2020

Deutsche Physikalische Gesellschaft

For the age range from 1.5 to 4 Myr ago we found in deep oceanferromanganese crusts an excess concentration in terms of 53Mn/Mnof about 4 · 10−14 over that expected for cosmogenic production. Weconclude that this 53Mn is of supernova origin because it is detected inthe same time window, about 2.5 Myr ago, where 60Fe has been foundearlier. This overabundance confirms unambiguously the supernova(SN) origin of that 60Fe. For the first time supernova-formed 53Mn hasbeen detected and it is the second positively verified radioisotope fromthe same supernovae. The ratio 53Mn/60Fe of about 12 is consistentwith that expected for a SN with a 11 - 25 M⊙ progenitor mass andsolar metallicity. A fit over the whole range until 10 Myr shows alsoa second increase of 53Mn/Mn in the range around 6 Myr matchingrecent 60Fe detection in sediments at ANU.