Gold born in supernovae and neutron star collisions
The place does gold come from? It comes from the ground, in fact, however Earth’s gold originated in outer space. It’s produced in supernovae (exploding stars), and in neutron star collisions, in a set of nuclear reactions identified to scientists because the r-process. Astronomers utilizing state-of-the-art telescopes have found lots of of gold-rich stars in our Milky Way galaxy. However they’ve needed to know when, the place, and the way these stars fashioned. On November 14, 2022, the Royal Astronomical Society – primarily based in London – introduced a brand new numerical simulation, exhibiting that almost all gold-rich stars had been fashioned in low-mass dwarf galaxies that merged with our Milky Way some 10 billion years in the past.
They mentioned this new work sheds mild on these stars’ previous for the primary time. And so they identified that gold-rich stars compose a “fossil document,” thus giving astronomers a brand new instrument to make use of in probing our galaxy’s historical past.
The scientists conducting the examine are from the College of Notre Dame and Tohoku College. The analysis appears within the peer-reviewed scientific journal Month-to-month Notices of the Royal Astronomical Society.
Tracing Milky Way historical past
These astronomers are utilizing the time period “gold-rich” to explain stars that comprise excessive abundances of heavy parts (these heavier than iron), together with what they referred to as “jewellery retailer parts,” gold and platinum.
They used the ATERUI II supercomputer within the Centre for Computational Science on the Nationwide Astronomical Observatory of Japan to provide their numerical simulation. They mentioned it tracks the Milky Way’s formation from the Huge Bang to the current, with a excessive stage of element with respect to time. They mentioned:
This simulation has the very best time resolution but achieved: it may exactly resolve the cycle of supplies fashioned by stars within the Milky Way …
The usual cosmology it used predicts that the Milky Way grows by the accretion and merging of small progenitor galaxies [the small galaxies that merged with our Milky Way to create the large galaxy we live in today].
Gold-rich stars as ‘fossils’
The simulation information revealed that a number of the progenitor galaxies – people who existed over 10 billion years in the past – contained massive quantities of the heaviest parts. These heavy parts got here from neutron star mergers, they mentioned, a identified supply of heavy component creation. They mentioned:
The gold-rich stars fashioned in these galaxies, and their predicted abundances will be in contrast with the observations of the celebs right now.
Yutaka Hirai of Tohoku College commented:
The gold-rich stars right now inform us the historical past of the Milky Way. We discovered most gold-rich stars are fashioned in dwarf galaxies over 10 billion years in the past. These historic galaxies are the constructing blocks of the Milky Way.
Our findings imply most of the gold-rich stars we see right now are the fossil data of the Milky Way’s formation over 10 billion years in the past.
And he added:
Comparability with simulations and observations within the Milky Way opens a brand new avenue for extracting the fossil data of stars.
Backside line: New pc simulations are exhibiting that almost all gold-rich stars had been fashioned in low-mass dwarf galaxies that merged with our Milky Way galaxy some 10 billion years in the past.
