[ RadSafe ] Hebrew University Team Uncovers Origin of Heavy Elements in the Universe
PHILIP.KARAM at nypd.org
Mon Dec 14 09:07:19 CST 2015
Interesting piece, and it adds a bit to the existing thinking by adding a new source of Pu-244. But it still seems likely that a great deal of Pu-244 is formed in supernovae, with the binary neutron star mergers adding to the supernova-produced material.
One thing, too, to consider is that the Solar System is in a "superbubble" - an area of space in which cosmic gas and dust concentrations are much lower than is typical in our galaxy. One line of thinking is that this superbubble was carved out by a series of supernovae a few tens of millions of years ago - the shock waves from the supernovae are thought to have propelled the gas and dust from this area. So one reason for the paucity of Pu-244 that was mentioned could well be the Solar System's presence in a part of space that is abnormally clear of debris.
The reason for the early Solar System containing a bunch of Pu-244 (as mentioned in this piece) could be that the dust cloud from which the Solar System formed was, itself, supernovae debris and the impetus for it to begin collapsing into the Sun and planets was most likely being struck by the shock wave from another supernova. So it's not surprising that the earliest Solar System would have elevated levels of this nuclide.
Anyhow - it seems most reasonable to think that Pu-244 is formed in supernovae AND in binary star mergers; the supernovae would provide the "background" Pu-244 and the binary star mergers would punctuate that with occasional injections of larger amounts.
P. Andrew Karam, PhD, CHP
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From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of ROY HERREN
Sent: Sunday, December 13, 2015 6:15 AM
Subject: [ RadSafe ] Hebrew University Team Uncovers Origin of Heavy Elements in the Universe
Hebrew University Team Uncovers Origin of Heavy Elements in the Universe _______________________________________________
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