August 4, 2017 Artists depiction of a neutron star. Credit: NASA

Astronomers like to say we are the byproducts of stars, stellar furnaces that long ago fused hydrogen and helium into the elements needed for life through the process of stellar nucleosynthesis.

As the late Carl Sagan once put it: "The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff."

But what about the heavier elements in the periodic chart, elements such as gold, platinum and uranium?

Astronomers believe most of these "r-process elements"elements much heavier than ironwere created, either in the aftermath of the collapse of massive stars and the associated supernova explosions, or in the merging of binary neutron star systems.

"A different kind of furnace was needed to forge gold, platinum, uranium and most other elements heavier than iron," explained George Fuller, a theoretical astrophysicist and professor of physics who directs UC San Diego's Center for Astrophysics and Space Sciences. "These elements most likely formed in an environment rich with neutrons."

In a paper published August 7 in the journal Physical Review Letters, he and two other theoretical astrophysicists at UCLAAlex Kusenko and Volodymyr Takhistovoffer another means by which stars could have produced these heavy elements: tiny black holes that came into contact with and are captured by neutron stars, and then destroy them.

Neutron stars are the smallest and densest stars known to exist, so dense that a spoonful of their surface has an equivalent mass of three billion tons.

Tiny black holes are more speculative, but many astronomers believe they could be a byproduct of the Big Bang and that they could now make up some fraction of the "dark matter"the unseen, nearly non-interacting stuff that observations reveal exists in the universe.

If these tiny black holes follow the distribution of dark matter in space and co-exist with neutron stars, Fuller and his colleagues contend in their paper that some interesting physics would occur.

They calculate that, in rare instances, a neutron star will capture such a black hole and then devoured from the inside out by it. This violent process can lead to the ejection of some of the dense neutron star matter into space.

"Small black holes produced in the Big Bang can invade a neutron star and eat it from the inside," Fuller explained. "In the last milliseconds of the neutron star's demise, the amount of ejected neutron-rich material is sufficient to explain the observed abundances of heavy elements."

"As the neutron stars are devoured," he added, "they spin up and eject cold neutron matter, which decompresses, heats up and make these elements."

This process of creating the periodic table's heaviest elements would also provide explanations for a number of other unresolved puzzles in the universe and within our own Milky Way galaxy.

"Since these events happen rarely, one can understand why only one in ten dwarf galaxies is enriched with heavy elements," said Fuller. "The systematic destruction of neutron stars by primordial black holes is consistent with the paucity of neutron stars in the galactic center and in dwarf galaxies, where the density of black holes should be very high."

In addition, the scientists calculated that ejection of nuclear matter from the tiny black holes devouring neutron stars would produce three other unexplained phenomenon observed by astronomers.

"They are a distinctive display of infrared light (sometimes termed a "kilonova"), a radio emission that may explain the mysterious Fast Radio Bursts from unknown sources deep in the cosmos, and the positrons detected in the galactic center by X-ray observations," said Fuller. "Each of these represent long-standing mysteries. It is indeed surprising that the solutions of these seemingly unrelated phenomena may be connected with the violent end of neutron stars at the hands of tiny black holes."

Explore further: New simulations could help in hunt for massive mergers of neutron stars, black holes

More information: Primordial black holes and r-process nucleosynthesis, Physical Review Letters (2017). journals.aps.org/prl/accepted/ 5a1a918b69bd6d2e6077

Now that scientists can detect the wiggly distortions in space-time created by the merger of massive black holes, they are setting their sights on the dynamics and aftermath of other cosmic duos that unify in catastrophic ...

The lightest few elements in the periodic table formed minutes after the Big Bang. Heavier chemical elements are created by stars, either from nuclear fusion in their interiors or in catastrophic explosions. However, scientists ...

A globular cluster is a roughly spherical ensemble of stars (as many as several million) that are gravitationally bound together, and typically located in the outer regions of galaxies. Low mass X-ray binary stars (LMXBs) ...

NASA's Neutron Star Interior Composition Explorer, or NICER, is an X-ray telescope launched on a SpaceX Falcon 9 rocket in early June 2017. Installed on the International Space Station, by mid-July it will commence its scientific ...

A group of astronomers have shown that the fastest-moving stars in our galaxy - which are travelling so fast that they can escape the Milky Way - are in fact runaways from a much smaller galaxy in orbit around our own.

Professor Sudip Bhattacharyya of the Tata Institute of Fundamental Research (TIFR), Mumbai, India, and Professor Deepto Chakrabarty (MIT), an adjunct visiting professor at the same institute, have shown that a population ...

(Phys.org)Quantum engines are known to operate differently thanand in some cases, outperformtheir classical counterparts. However, previous research on the performance of quantum engines may be overestimating their ...

Astronomers like to say we are the byproducts of stars, stellar furnaces that long ago fused hydrogen and helium into the elements needed for life through the process of stellar nucleosynthesis.

Researchers at North Carolina State University and Duke University have developed a way to assemble and pre-program tiny structures made from microscopic cubes - "microbot origami" - to change their shape when actuated by ...

Imperial researchers have tested a 'blued' gauntlet from a 16th-century suit of armour with a method usually used to study solar panels.

In general, solid state physicists are not able to separate the two processes, so they cannot answer the question, whether the magnetic order is indeed reduced, or whether it is just hidden.

Astrophysicists have a fairly accurate understanding of how the universe ages: That's the conclusion of new results from the Dark Energy Survey (DES), a large international science collaboration, including researchers from ...

Adjust slider to filter visible comments by rank

Display comments: newest first

how/massive/are/the/black/holes/they/modelled?

On topic of article, it is most plausible that elements (especially the heavier variety) transmute from neutron matter. It is widely known that a neutron in free space decays into a hydrogen atom. I conjecture that inside of stars it is not the proton proton chain reaction that leads to helium production but rather quad neutron convergence that results in helium. I'd venture so far as to say that just as in free space neutrons decay into a proton and electron, the inverse occurs under the immense pressures in the cores of stars. Hydrogen converts to neutrons.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Go here to see the original:

Primordial black holes may have helped to forge heavy elements - Phys.Org