Tuesday, 28 October 2014
Scientists Create 3D Map of Cosmic Web for the First Time Showing 'Adolescent' Universe
Using extremely faint light from galaxies 10.8 billion light-years away, scientists created one of the most complete, 3D maps of the early universe. 3D map of the cosmic web at a distance of 10.8 billion years from Earth, generated from imprints of hydrogen gas observed in the spectrum of 24 background galaxies behind the volume. (Photo : Casey Stark (UC Berkeley) and Khee-Gan Lee (MPIA))
y have managed to create a map of what our universe looked like during its adolescence. Using extremely faint light from galaxies 10.8 billion light-years away, the researchers created one of the most complete, 3D maps at a time when the universe was made of a fraction of the dark matter we see today.
In this case, the researchers used a new technique for high-resolution universe maps. This technique, which uses distant galaxies to backlight hydrogen gas, could actually also inform future mapping projects, such as the proposed Dark Energy Spectroscopic Instrument (DESI).
Before this study, no one knew if galaxies further than 10 billion light-years away could provide enough light to be useful. Yet the Keck-1 telescope collected four hours of data during a brief break in cloudy skies and showed that it was possible to do so. Because of the extreme faintness of the light, though, the scientists had to develop algorithms to subtract light from the sky that would otherwise drown out the galactic signals.
"It's a pretty weird map because it's not really 3D," said David Schlegel, one of the researchers, in a news release. "It's all these skewers; we don't have a picture of what's between the quasars, just what's along the skewers."
The resulting map, though, shows that this technique is possible for future maps.
"This technique is pretty efficient and it wouldn't take a long time to obtain enough data to cover volumes hundreds of millions of light-years on a side," said Khee-Gan Lee, the lead researcher.
The findings reveal a bit more about the early universe and show that this technique could be huge when it comes to peering even further back into the past. That said, scientists will need to collect more data before this becomes a possibility.
Source : Science World Report