Study suggests an even distribution of elements throughout the
universe
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Anthony Wood
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October 28, 2015
Visible light image of the Virgo Galaxy Cluster (Credit:
NOAO/AURA/NSF)
A new study carried out by the Japan Aerospace
Exploration Agency (JAXA) suggests that when the universe was
between two to four billion years old, the elements used to create
everything from the largest star to the human race were evenly
spread across a vast area of the cosmos. The study focused on an
enormous structure of galaxies known as the Virgo Galaxy Cluster,
which sits roughly 54 million light years from Earth and harbors
over 2,000 galaxies.
The study drew from observations made by JAXA's Suzaku
X-ray satellite, a long-serving X-ray telescope that has since been
decommissioned due to the deteriorating health of the spacecraft. To
make the necessary observations, Suzuka targeted a 5 million light
year stretch of each of the four arms extending from the center of
the enormous Virgo Galaxy Cluster.
The cluster is the second brightest ever discovered, making it an
obvious focus for the study. Furthermore the sheer size of the cosmic
structure allows astronomers to use the results of the study to
extrapolate the chemical make-up of the Universe as a whole.
Graphic showing Suzaku images of the four arms of the Virgo
Galaxy Cluster
Data collected by Suzuka of the Virgo cluster detected the signature
of both heavier and lighter elements evenly distributed throughout the
vast region.
"Heavier chemical elements from carbon on up are produced and
distributed into interstellar space by stars that explode as supernovae
at the ends of their lifetimes," states Aurora Simionescu, leader of the
team of astrophysicists at JAXA who made the observations. "This
chemical dispersal continues at progressively larger scales through
other mechanisms, such as galactic outflows, interactions and mergers
with neighboring galaxies, and stripping caused by a galaxy's motion
through the hot gas filling galaxy clusters."
It is believed that different types of supernovae are responsible for
spreading distinct elements across the galaxy cluster. For example stars
in excess of eight times the mass of our Sun that collapse into what is
known as a core-collapse supernova, spread elements such as oxygen and
silicon. White dwarfs, which end their lives in what is known as a
Type Ia supernova, otherwise known as a "standard candle,"
distribute vast quantities of iron and nickel.
Previous observations of the Perseus Galaxy Cluster had displayed an
even distribution of iron throughout the structure, but had been unable
to ascertain the spread of lighter elements. Data from the Virgo cluster
study appears to fill in these gaps, with the data displaying an even
distribution of iron, magnesium, silicon and sulfur across the leviathan
structure.
According to the study, these elemental ratios are fairly consistent
with the make up of stars in the Milky Way, including our own Sun. This
tells us that the chemical composition of the Universe is extremely well
mixed, and that the mechanisms and supernovae ratios that determined the
composition of our galaxy are in effect throughout the universe.
A paper detailing the findings has been published in
The Astrophysical Journal.
Source:
NASA
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