Tag Archives: SDSS

Looks Like Einstein Was Right

Yesterday, in the journal Nature, astrophysicists announced that data they utilized from the Sloan Digital Sky Survey (SDSS) has led them to the conclusion that Einstein’s General Theory of Relativity is valid. The astronomers used a “map of the distribution of galaxies in the Sloan Digital Sky Survey, going out to a distance of 7 billion light years.” The authors conclude that “the existence of dark matter is the most likely explanation for the observation that galaxies and galaxy clusters move as if under the influence of some unseen mass, in addition to the stars astronomers observe.” Read the announcement from UC Berkeley online here, or read the entire science paper online here.

Astronomers Seek to Understand “Green Peas”

In a paper to be published in the Monthly Notices of the Royal Academy of Sciences, available online now here, a team of astronomers review the latest known about an unusual class of galaxies known as “Green Peas.” This is all a result of a project called the Galaxy Zoo, wherein astronomers have enlisted the aid of over 200,000 professional astronomers, amateur astronomers and students in classifying galaxies as seen by the Sloan Digital Sky Survey (SDSS). The galaxies nicknamed green peas, are characterized by being low mass and having high star formation rates. Now in this case low mass galaxies have less than 10 billion solar mass equivalent stars, and have star formation rates higher than 10 solar mass stars forming every year. If you wish to participate in the Galaxy Zoo project, you can join in at their website.

A Review of the Large Scale Structure

In a non-mathematical review prepared for a conference, available online here, astronomer Jaan Einasto provides the general reader with a review of our understanding of the large scale structure of the universe. Dr. Einasto makes use of data and imagery from the Sloan Digital Sky Survey (SDSS) and includes simulations of the evolution of superclusters in the universe.

In Search of Gravitational Lenses

The gravitational lens effect (bending of light by gravity) was first predicted by Einstein with his General Theory of Relativity. It was originally demonstrated shortly after the World War I utilizing our Sun at the time of a total solar eclipse. It has since been instrumental in investigating the most distant galaxies in the universe. Learn about the latest gravitational lensing analyses of distant galaxies online at http://xxx.lanl.gov/PS_cache/arxiv/pdf/0812/0812.3934v1.pdf This group of astronomers utilized the Sloan Digital Sky Survey. You can see images from this bright arc survey online at http://home.fnal.gov/~kubo/brightarcs.html The most distant of the galaxies discussed are estimated to be close to 8 billion light years distant.