Sloan Spots One Hundred Thousand Black Hole Behemoths

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Sloan 2.5-meter Telescope, with the building rolled away and inside its wind protective shield. Sacramento Mountains in the background. Image Credit: Fermilab Visual Media Services and SDSS.

The Sloan Digital Sky Survey (SDSS) has mapped the sky and created a database of millions of objects for astronomers to study. This, all with a 2.5-meter telescope in New Mexico. The latest data release catalogs 105,783 quasars, or the active centers of distant galaxies with supermassive black holes.

At the time that SDSS began, only 6,000 quasars were known. Now, this huge database gives the positions, colors, and distances of over 100,000 quasars. The most distant of these is over 12.5 billion light years away, meaning that its light reaches us from when the universe was just over a billion years old.

WIDE ANGLE: Black Holes, Big and Small

This kind of project has been a major shift away from small teams studying individual objects with their telescope time. These data are taken and analyzed and made available to the entire astronomical community, such that a researcher or student at any institution can go in with an idea and use these massive catalogs to do their science.

The catalog, led by Donald Schneider of Penn State University, is being published by Astrophysical Journal this month, but can also be perused online via Arxiv.org. However, one of the most useful tool for accessing SDSS data is the SkyServer, so get cracking on some discoveries, astronomers!

Now that the main mission of SDSS is complete, what will become of the 2.5-meter telescope at Apache Point? Its days of discovery are not done yet. Astronomers from the member institutions of the Sloan collaboration are gearing up for new survey that will answer questions about the extended halo of our Galaxy, the chemistry of stars, exoplanets, and dark energy. When you have an instrument that works so well, it pays to keep using it to explore new horizons.