One moment *way* back in time

What did the universe look like 11 billion years ago? Something like this:

SDSS-II map slice.jpg

This image is part of the largest-ever 3-D map of the distant universe, which was released yesterday by scientists from the Sloan Digital Sky Survey III (SDSS-III) at the April meeting of the American Physical Society. Just a slice of the entire map, the image shows the distribution of intergalactic hydrogen gas: red areas have more gas, blue areas have less.

Scientists usually map the universe by looking at galaxies. But this study, which was led by Brookhaven cosmologist Anže Slosar, observed how light from quasars -- among the brightest objects in the universe -- is blocked as it passes through clouds of hydrogen gas.

As quasar light journeys toward Earth, it gets absorbed by hydrogen gas at specific wavelengths, depending upon the distance traveled. This results in an irregular pattern on the quasar light known as the "Lyman-alpha forest." To get a full, 3-D map, the scientists, from SDSS-III's Baryon Oscillation Spectroscopic Survey (BOSS) collaboration, analyzed 14,000 quasars.

3D map_2.jpg
A slice through the three-dimensional map of the universe. SDSS-III scientists are looking out from the Milky Way, at the bottom tip of the wedge. Distances are labeled on the right in billions of light-years. The black dots going out to about 7 billion light years are nearby galaxies. The red cross-hatched region could not be observed with the SDSS telescope, but the future BigBOSS survey, the proposed successor to BOSS, could observe it. The colored region shows the map of intergalactic hydrogen gas in the distant universe. Red areas have more gas; blue areas have less gas.

More like this

On Brookhaven Bits & Bytes, Kendra Snyder shows us new images from the Sloan Digital Sky Survey III, which analyzed the light of 14,000 distant quasars to map the ancient universe in 3-D. Hydrogen gas absorbs the light from quasars at certain wavelengths, generating a pattern known as the "…
This guest post is written by BNL cosmologist Anže Slosar. Slosar, who joined Brookhaven's physics department in 2009, received his Ph.D. from Cambridge University in 2003. He previously worked at Lawrence Berkeley National Laboratory, Oxford University, and the University of Ljubljana in Slovenia…
“Despite its name, the big bang theory is not really a theory of a bang at all. It is really only a theory of the aftermath of a bang.” -Alan Guth When we look to the deepest reaches of space, we can look for the “first” of any type of object. The first galaxy, the first star, the first light from…
"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." -Carl Sagan Our night sky, quite literally, is our window to the Universe. Image credit: Miloslav…