After five years of peering into the deepest reaches of space, astrophysicists have created the largest-ever three-dimensional map of the universe and it encompasses more than 2 million galaxies and supermassive black holes.
The effort, which involved more than 100 astrophysicists from around 30 institutions worldwide, was built on 20 years of scientific observations.
According to theconferencenews.com, the mind-boggling map is the result of an ongoing project called the Sloan Digital Sky Survey (SDSS) — an ambitious, international quest to map the expansion of the observable universe, and hopefully solve a few cosmic conundrums in the process. Dr. Kyle Dawson, a cosmologist at the University of Utah, lead the Sloan Digital Sky Survey (SDSS) team which worked to fill in that gap.
“We know both the ancient history of the universe and its recent expansion history fairly well, but there’s a troublesome gap in the middle 11 billion years,” said Dr Kyle Dawson.
Their results were produced in an international collaboration with more than 100 astrophysicists taking part in something called the extended Baryon Oscillation Spectroscopic Survey (eBOSS). The survey captured detailed measurements of more than two million galaxies and quasars, covering 11 billion years of cosmic spacetime.
Crucially it established for certain a cosmological mystery which has baffled astronomers for decades: the mismatch in the Hubble Constant. The Hubble Constant is based on the observation that the universe is expanding, which we know because galaxies which are further away from Earth are moving even further away faster than galaxies which are closer.
But the survey also revealed that nobody can agree how fast the universe is expanding, and the new survey confirms that different parts seem to be expanding at different speeds – all apparently along the same flat axis, although it does exhibit a geometric curve.
Individual groups in the eBOSS team at universities around the world analysed different areas, creating different parts of the map using galaxies emitting different wavelengths of light. “To create the part of the map dating back six billion years, the team used large, red galaxies. Farther out, they used younger, blue galaxies,” said SDSS.
“Finally, to map the universe eleven billion years in the past and more, they used quasars, which are bright galaxies lit up by material falling onto a central supermassive black hole.” Each of these samples required careful analysis in order to remove contaminants, and reveal the patterns of the universe,” the researchers said.