Supernova Triggers for End-Devonian Extinctions?. (arXiv:2007.01887v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Fields_B/0/1/0/all/0/1">Brian D. Fields</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Melott_A/0/1/0/all/0/1">Adrian L. Melott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ellis_J/0/1/0/all/0/1">John Ellis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ertel_A/0/1/0/all/0/1">Adrienne F. Ertel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fry_B/0/1/0/all/0/1">Brian J. Fry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lieberman_B/0/1/0/all/0/1">Bruce S. Lieberman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_Z/0/1/0/all/0/1">Zhenghai Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miller_J/0/1/0/all/0/1">Jesse A. Miller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Thomas_B/0/1/0/all/0/1">Brian C. Thomas</a>
The Late Devonian was a protracted period of low speciation resulting in
biodiversity decline, culminating in extinction events near the
Devonian-Carboniferous boundary. Recent evidence indicates that the final
extinction event may have coincided with a dramatic drop in stratospheric
ozone, possibly due to a global temperature rise. Here we study an alternative
possible cause for the postulated ozone drop: a nearby supernova explosion that
could inflict damage by accelerating cosmic rays that can deliver ionizing
radiation for up to $sim 100$ kyr. We therefore propose that end-Devonian
extinction was triggered by one or more supernova explosions at $sim 20 rm
pc$, somewhat beyond the “kill distance” that would have precipitated a full
mass extinction. Nearby supernovae are likely due to core-collapses of massive
stars in clusters in the thin Galactic disk in which the Sun resides. Detecting
any of the long-lived radioisotopes sm146, u235 or pu244 in one or more
end-Devonian extinction strata would confirm a supernova origin, point to the
core-collapse explosion of a massive star, and probe supernova nucleosythesis.
Other possible tests of the supernova hypothesis are discussed.
The Late Devonian was a protracted period of low speciation resulting in
biodiversity decline, culminating in extinction events near the
Devonian-Carboniferous boundary. Recent evidence indicates that the final
extinction event may have coincided with a dramatic drop in stratospheric
ozone, possibly due to a global temperature rise. Here we study an alternative
possible cause for the postulated ozone drop: a nearby supernova explosion that
could inflict damage by accelerating cosmic rays that can deliver ionizing
radiation for up to $sim 100$ kyr. We therefore propose that end-Devonian
extinction was triggered by one or more supernova explosions at $sim 20 rm
pc$, somewhat beyond the “kill distance” that would have precipitated a full
mass extinction. Nearby supernovae are likely due to core-collapses of massive
stars in clusters in the thin Galactic disk in which the Sun resides. Detecting
any of the long-lived radioisotopes sm146, u235 or pu244 in one or more
end-Devonian extinction strata would confirm a supernova origin, point to the
core-collapse explosion of a massive star, and probe supernova nucleosythesis.
Other possible tests of the supernova hypothesis are discussed.
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