Dark Matter, Dark Energy and the Distant Universe.
This is a still image from a video fly-through of the SDSS-III galaxies mapped in Data Release 9. Credit: Miguel A. Aragón (Johns Hopkins University), Mark SubbaRao (Adler Planetarium), Alex Szalay (Johns Hopkins University), Yushu Yao (Lawrence Berkeley National Laboratory, NERSC), and the SDSS-III Collaboration
If you thought your Garmin was great, then you ought to take a gander at the largest ever three-dimensional map of massive galaxies and distant black holes.
Produced by the Sloan Digital Sky Survey III, this unique visual catalog of the cosmos will aid astronomers in their studies of dark matter and dark energy. However, that’s not all. The SDSSIII map has only completed one third of its mission, yet already encompasses over a million galaxies in a total volume equivalent to that of a cube four billion light-years on a side.
“We want to map the largest volume of the Universe yet, and to use that map to understand how the expansion of the Universe is accelerating,” said Daniel Eisenstein (Harvard-Smithsonian Center for Astrophysics), the director of SDSS-III.
Sloan Digital Sky Survey telescope (Photo credit: Wikipedia)
“What really makes me proud of this survey is our commitment to creating a legacy for the future,” said Michael Blanton, a New York University physics professor who led the team that prepared DR9. “Our goal is to create a map of the Universe that will be used long after we are done, by future generations of astronomers, physicists, and the general public.”
Dubbed DR9, this edition is the latest in a data set that began eleven years ago and includes new information gathered by the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). When the mission is completed it will have pinpointed the location of a million and a half massive galaxies over seven billion light years – along with 160,00 quasars at a distance of 12 billion light years.
The BOSS is eyeing these huge, bright galaxies because they are easier to spot and they reside in fainter galaxy fields. The DR9 map will act as a “history teacher” revealing seven billion years of cosmological action. This will help researchers better determine the ratios of dark matter and dark energy contained within our visible limits.
“Dark matter and dark energy are two of the greatest mysteries of our time,” said David Schlegel of Lawrence Berkeley National Laboratory, who led the SDSS-III effort to map these galaxies and quasars. “We hope that our new map of the Universe can help someone solve the mystery.”
According to the press release, this new map contains information on 200 million galaxies and spectra of 1.35 million galaxies, including new spectra of 540,000 galaxies from when the Universe was half its present age. Each bit of information acts as a clue to distance – longer in the red wave length which helps to imply expansion.
Quasars also help in measurements. Their spectra aids in the identification of huge intergalactic gas masses and the possible location of dark matter between each quasar and Earth. This new data not only improves our understanding of the Universe as a whole, but also enlightens us about the structure of the Milky Way.
“With these better estimates, we can look back at the history of our galaxy,” said Connie Rockosi of the University of California, Santa Cruz, who leads the SDSS-III’s Milky Way study. “We can tell the story of how smaller galaxies came together to build up the Milky Way we see today.”
All these new images and spectra contain the promise of new discoveries about our Universe — but the SDSS-III is only in the middle of its six-year survey.
“The most fun part of making this data available online is knowing that anyone on the Internet can now access the very same data and search tools that professional astronomers use to make exciting discoveries about our Universe,” said Ani Thakar of Johns Hopkins University.
Does DR9 end here? Not hardly. There’s much more information hidden inside – waiting to be uncovered.
“This is science at its collaborative best,” said Michael Wood-Vasey, a professor at the University of Pittsburgh and the scientific spokesperson for the SDSS-III collaboration. “SDSS-III scientists work together to address big questions extending from our own galaxy to distant reaches of the Universe and then they share all of that data with the world to allow anyone to make the next big discovery.”
Original Story Source: Harvard Smithsonian Center for Astrophysics.
