The Universe may have more methods than we imagined to create heavy elements. Metals like gold, silver, thorium, and uranium need very extreme circumstances such as a supernova explosion or a neutron star collision to form.
However, a new article suggests that these materials might emerge in the whirling maelstrom surrounding an active newborn black hole as it consumes dust and gas from the surrounding Universe. The high neutrino emission rate in these severe conditions should assist the conversion of protons to neutrons, resulting in more than the latter, which is necessary for making heavy elements.
“In our study, we systematically investigated the conversion rates of neutrons and protons for a large number of disc configurations for the first time using elaborate computer simulations, and we discovered that the discs have numerous neutrons as long as the conditions meet,” said astrophysicist Oliver Just. There weren’t a lot of components floating around in the beginning, following the Big Bang. The Universe was all hydrogen and helium until stars were created and began smashing atomic nuclei together in their centers.
Stellar nuclear fusion filled the Universe with heavier elements, ranging from carbon to iron for the most massive stars, scattered across space after the principal dies. However, iron is where core fusion fails. The heat and energy necessary to manufacture iron via fusion surpass the power generated by the process, causing the core temperature to plummet and the star to die in a magnificent kaboom – the supernova.
The heavier atoms are fused in that stunning kaboom (and the kabooms of colliding neutron stars). The explosions are so powerful that particles interacting with enough force may grab neutrons from one another. This process is called rapid neutron capture or r-process; it must proceed fast so that radioactive decay does not begin before further neutrons are added to the nucleus.
It’s uncertain if the r-process can occur in other settings, but infant black holes are a plausible contender. When neutron stars merge, and their combined mass is sufficient to push the newly created object into the category of a black hole. Another option is collapsars, which are caused by the gravitational collapse of the core of a giant star into a stellar-mass black hole.
In both circumstances, the infant black hole is considered to be encircled by a dense, hot ring of material that swirls around it and feeds into it like water down a drain. Neutrinos are abundant in these conditions, and astronomers have long suspected that r-capture nucleosynthesis is occurring as a result.
Just and his colleagues ran a slew of simulations to see if this was the case. They altered the black hole’s mass and spin, the group of the material around it, and the influence of different parameters on neutrinos. They discovered that r-process nucleosynthesis might take occur in these situations provided the circumstances are exactly perfect.
“The more massive the disc, the more often neutrons are generated from protons by electron capture and neutrinos emission, and are accessible for heavy element synthesis via the r-process.” “However, if the disk’s mass is too large, the inverse reaction becomes more active, and neutrons trap more neutrinos before they leave the disc.” These neutrons are subsequently transformed back to protons, causing the r-process to be slowed.”