Scientists Create Eye-Popping Map Of Distant Galaxies

The plot covers 650 billion cubic light-years and contains 1.2 million galaxies.

20/07/2016 12:25 AM AEST | Updated 20/07/2016 12:25 AM AEST
Daniel Eisenstein, SDSS-III collaboration
One slice through the new map. Each dot in the image, which covers about 1/20th of the sky, represents the position of a galaxy 6 billion years in the past. Color indicates distance from Earth -- yellow on the near side of the slice to purple on the far side. Gray patches are regions for which survey data are lacking.

In an effort to gain a better understanding of the mysterious gravity-counteracting force known as dark energy, scientists have teamed up to create the largest-ever three-dimensional map of distant galaxies.

“We have spent a decade collecting measurements of 1.2 million galaxies over one quarter of the sky to map out the structure of the universe over a volume of 650 billion cubic light-years,” Dr. Jeremy Tinker, a scientist at New York University’s Center for Cosmology and Particle Physics and a co-leader of the scientific team that created the map, said in a news release.

(In case you’re wondering just how vast 650 billion cubic light-years really is, it’s equivalent to the volume inside a cube that measures almost 51,000,000,000,000,000 miles on each side.)

The map “has allowed us to make the best measurements yet of the effects of dark energy in the expansion of the universe,” Tinker continued. And the measurements show, he said in an email to The Huffington Post, that “Einstein was right once again” about gravity.

Or, as Dr. Rita Tojeiro, a research fellow in physics and astronomy at the University of St. Andrews in Scotland and the teams’ other co-leader, told The Huffington Post in an email, the map confirms our standard model of cosmology.”

Jeremy Tinker, SDSS-III
The researchers have transformed a two-dimensional image of the sky (left panel) into a three-dimensional map spanning billions of light-years, shown here from two perspectives (middle and right panels). This map includes 120,000 galaxies over 10 percent of the survey area. The bright areas correspond to the regions of the universe with more galaxies and therefore more dark matter.

Though nonscientists often think of the universe as simply a collection of stars and planets spread throughout space, the reality is a bit more complicated. We now know, for instance, that more than 90 percent of the universe is “dark,” either in the form of a mysterious substance known as dark matter (25 percent of the universe) or the little-understood force known as dark energy (70 percent of the universe).

We still can’t see the dark parts of the universe, but the map helps show how they affect the visible parts.

“In this map, we can see galaxies being gravitationally pulled toward other galaxies by dark matter,” Dr. David Schlegel, an astrophysicist at Berkeley National Laboratory and another key scientist behind the map, said in another release. “And on much larger scales, we see the effect of dark energy ripping the universe apart.”

The measurements used to create the map were obtained by hundreds of scientists from several institutions associated with the Sloan Digital Sky Survey III (SDSS-III), the Christian Science Monitor reported. SDSS-III is an astronomy initiative that aims to map the Milky Way galaxy, search for exoplanets and create a better understanding of dark energy.

A set of scientific papers describing the map was submitted to Monthly Notices of the Royal Astronomical Society, and these are just “the tip of the iceberg,” according to Tojeiro.

She said the scientific community would use the map and the associated data “for a wide range of science, from exploring specific cosmological and gravity models to understanding themselves have evolved.”

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