Astronomers worked on the largest and most detailed 3D map of the ancient universe using light from 14, 000 distant but powerful cosmic beacons.
This latest version plotted clouds of hydrogen in a swath between 10 billion and 12 billion light-years away compared to the previous versions that showed the locations of galaxies with 7 billion light-years of Earth.
These hydrogen clouds could help give clarification to the astronomers’ more profound questions regarding the universe like the nature of dark energy.
One of the researchers cosmologist Anže Slosar of Brookhaven National Laboratory, who presented the map on May 1 at the American Physical Society meeting in Anaheim, California said, “We’re looking for a bump in the data that may tell us how fast universe is expanding. We don’t have enough data to see the bump yet, but we expect to get there in a few years.”
This third iteration by the Sloan Digital Sky Survey uses a multipurpose telescope which hosts an instrument called the Baryon Oscillation Spectroscopic Survey, or BOSS that could interpret light from individual quasars.
“Quasars are extremely bright galaxies that are very far away. At the center of each, a black hole is eating matter. The matter heats up to such super high temperatures that it shines like crazy,” Slosar said. “This allows us to see them from very, very far away.”
This light from quasars focuses into a beam which gets partially absorbed by hydrogen gas as it passes to Earth. It will then be re-emitted in a different wavelength that will create a unique spectrum for each quasar. The beam traverses space and time, and because of this, astronomers can use its spectrum to estimate hydrogen cloud expansions and contractions.
This latest breakthrough painstakingly analyzed 4, 000 of about 160, 000 known quasars. The astronomers hope to have 50, 000 or 60, 000 quasar slices at hand by 2014 — maybe enough to discover something memorable about the universe.
photo credit: wired.com