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usefulmistakes:
‘Wasteful’ galaxies don’t recycle as much as we thought
Without heavy elements you couldn’t read this because you wouldn’t
exist. In fact no life would, or any planets anywhere in the universe.
Vital heavy elements such as carbon, oxygen and zinc are made by
fusing lighter elements together under incredible conditions of intense
heat, pressure and energy found inside the heart of stars, or during
violent supernova explosions.
It’s amazing that many of the atoms in your body were forged during
nuclear explosions deep within stars and then blasted into space when
they died. But it turns out that this process is pretty wasteful, and
that enormous quantities of these precious elements are lost when
explosions from supernovae and supermassive black holes propel them far
beyond galaxies - sometimes up to a million light years into deep
space.
An international research team showed that more oxygen, carbon and
iron atoms exist in the sprawling, gaseous halos outside of galaxies
than within them, depriving galaxies of raw materials for stars and
planets.
The near-invisible reservoir of gas that surrounding a galaxy is
called the circumgalactic medium (CGM). Using a $70m instrument on board
the NASA Hubble Space Telescope the researchers analysed the
composition of the CGM, which is near-invisible to human eyes. They were
surprised to see so many heavy elements in the CGM as the assumption
had been that these elements would be reused to new planets and stars
more efficiently.
But as lead author Benjamin Oppenheimer, a research associate in the
Center for Astrophysics & Space Astronomy at CU-Boulder, said: “As
it turns out, galaxies aren’t very good at recycling.”
Images: Adrien Thob, LJMU, and NASA
The paper is published in Monthly Notices of the Royal Astronomical Society
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