A new map reveals our universe is more massive than we realize. Astronomers with the Baryon Oscillation Spectroscopic Survey (BOSS), a Sloan Digital Sky Survey III (SDSS-III) program, measured the galaxies in the universe in a “volume of 650 cubic billion light years” and created a map with a staggering 1.2 million galaxies. Not only does the map give us new perspective on the vastness of the universe, it helps astronomers measure mysterious dark energy.
The 3D map is the “largest-ever” of its kind and brings together around 10 years of work. One of the team leaders, New York University physics professor Jeremy Tinker, said in a press release, “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…This map has allowed us to make the best measurements yet of the effects of dark energy in the expansion of the Universe. We are making our results and map available to the world.” The rectangle in the image above includes just 10 percent of SDSS-III’s dataset.
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The dense map shown above may look like a collection of stars, but each of those dots is actually one galaxy from six billion years ago. This image only shows 3 percent of the entire dataset gathered by SDSS-III. Yellow dots are galaxies closest to Earth, and purple dots are the galaxies furthest away. There isn’t data available for the gray patches.
How do these maps provide insight into dark energy, the theoretical force propelling the universe’s expansion? Well, BOSS measures sound waves from the “young Universe” – when the universe was around 400,000 years old – and these sound waves helped astronomers make their map. They used the map to measure dark energy, which they believe is “driving the accelerated expansion of the Universe.” As Tinker noted, it’s one of the best measurements we’ve ever been able to make of dark energy.
The astronomers submitted their research to the journal Monthly Notices of the Royal Astronomical Society.
Images via Daniel Eisenstein and the SDSS-III collaboration and Jeremy Tinker and the SDSS-III collaboration
So the takeaway here is there are 4.8 million galaxies in the visible universe?