{"id":3318,"date":"2021-12-01T10:00:00","date_gmt":"2021-12-01T10:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=3318"},"modified":"2021-11-17T08:09:08","modified_gmt":"2021-11-17T08:09:08","slug":"where-does-gold-come-from-black-holes-with-accretion-disks-scientists-think","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/where-does-gold-come-from-black-holes-with-accretion-disks-scientists-think\/","title":{"rendered":"Where Does Gold Come From? Black Holes With Accretion Disks, Scientists Think"},"content":{"rendered":"\n

Earlier this year we at Modern Sciences did a piece on how the work of two bored astronomers gave us a more illustrated glimpse of the beginnings of the elements in the periodic table<\/a>; however, new findings published in the Monthly Notices of the Royal Astronomical Society<\/em> may shed some new light on the topic.<\/p>\n\n\n\n

An international team of experts, headed by scientists from Germany\u2019s GSI Helmholtzzentrum f\u00fcr Schwerionenforschung, took a deep dive into the details within black hole mechanics and phenomena using detailed computer simulations\u2014all in an attempt to get to the bottom of where heavy elements like gold (Au) and uranium (U) truly come from.<\/p>\n\n\n\n

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This piece of ore from Colorado, USA, shows patches of gold beneath and on its surface. According to our current understanding of the universe, elements like these are produced by rapid neutron capture processes (r-processes) birthed from the collisions of very dense objects like neutron stars. (St. John, 2014) <\/figcaption><\/figure><\/div>\n\n\n\n

Based on the currently accepted understanding in the sciences, heavy elements like gold and uranium are produced by the collisions of very massive objects like neutron stars and black holes, and was given credence by the detection of gravitational waves back in 2017<\/a>.<\/p>\n\n\n\n

However, a group of experts think there\u2019s much more left unexplored about the topic; this prompted Dr. Oliver Just, lead author and from GSI\u2019s Relativistic Astrophysics group, to get to the bottom of it all.<\/p>\n\n\n\n

Their prime candidate was black holes with accretion disks<\/em>, or a black hole surrounded by stellar material like gas and dust that orbit around the black hole. These black holes are likely formed from phenomena like the merger of two neutron stars. (Find out more about how black holes form in our earlier piece about them<\/a>.)<\/p>\n\n\n\n

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This blurry image of a black hole may look unremarkable to the untrained eye, but obtaining this photo encompassed decades of hard work, beginning with the conception of the theory by its progenitors decades ago. This very first visual observation of a black hole is of the one in the center of the Messier 87 (M87) Galaxy, and was taken by the Event Horizon Telescope back in 2017. (EHT Collaboration, 2019) <\/figcaption><\/figure><\/div>\n\n\n\n

Thing is, most experts think that heavy elements like gold are only produced under a high amount of neutrons, as this environment enables the rapid neutron capture process<\/em> (r-process) that most scientists think synthesize these rare elements across the universe.<\/p>\n\n\n\n

In their landmark study, Dr. Just and team \u201csystematically investigated […] the conversion rates of neutrons and protons for a large number of [accretion] disk configurations by means of elaborate computer simulations.\u201d<\/p>\n\n\n\n

It was only after combing through these simulations that they found some key details about how these heavy elements may form. For one, the mass of the accretion disk surrounding the black hole must play within 0.01 to 0.1 solar masses<\/em>, or 0.01 to 0.1 times the mass of our own Sun. Within this range, accretion disks become \u201cvery rich in neutrons,\u201d according to Dr. Just in a news release by EurekAlert!.<\/p>\n\n\n\n

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This animated visualization shows a black hole surrounded by an accretion disk. These accretion disks are said to be the birthplace of heavy elements like gold and uranium, but only under certain conditions. (NASA\u2019s Goddard Space Flight Center\/Jeremy Schnittman, 2019) <\/figcaption><\/figure><\/div>\n\n\n\n

These neutrons form as protons capture electrons; positive merges with negative, creating a neutron and releasing a neutrino<\/em>\u2014which is a nearly-massless, and also neutral, subatomic particle. According to the findings of Dr. Just and team, should a resulting black hole accretion disk land between the range of solar masses they described, neutrons are sure to be in plentiful supply, allowing the r-process to take place\u2014and, subsequently, the generation of heavy elements like gold and uranium.<\/p>\n\n\n\n

Data obtained from these simulations are expected to be augmented by data from the next generation of particle accelerators, like GSI\u2019s very own Facility for Antiproton and Ion Research (FAIR) that\u2019s currently under construction. Data from particle accelerators like FAIR can then be used to isolate and identify light signals gathered from these faraway accretion disks to truly ascertain the presence of these heavy elements.<\/p>\n\n\n\n

Said co-author Dr. Andreas Bauswein: \u201c[With] the next generation of accelerators, such as FAIR, it will be possible to measure [these light signals] with unprecedented accuracy in the future. The well-coordinated interplay of theoretical models, experiments, and astronomical observations will enable us researchers in the coming years to test neutron star mergers as the origin of the r-process elements.\u201d<\/p>\n\n\n\n

References<\/h2>\n\n\n\n