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Physics Professor David Rupke Publishes Groundbreaking Astronomy Research

Publication Date: 2/24/2011

The Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., has announced an important new discovery by David Rupke of Rhodes College and Sylvain Veilleux of the University of Maryland.

When two galaxies merge to form a giant, the new galaxy’s central black hole develops an insatiable appetite. The galaxy feeds the black hole the material it needs to grow, and simultaneously creates new stars in a dramatic burst of activity. This process, however, can be impeded by outflows of gas and dust (known as “galactic winds”) that carry away the material the black hole and new stars need to continue their feast. Without the matter to form new stars, the host galaxy starves to death, turning into a collection of old aging stars with few young stars to regenerate the stellar population.

Astronomers have for years claimed that such outflows are a crucial missing piece of the model for how galaxies evolve, but definitive observations have remained elusive. For the first time, Rupke and Veilleux’s observations with the Gemini Observatory clearly reveal an extreme, large-scale galactic outflow that is depriving the galaxy Markarian 231 (Mrk 231) of the material it needs to grow its central black hole and make a new generation of stars.

According to Veilleux, Mrk 231 is an ideal laboratory for studying outflows from supermassive black holes. “This object is arguably the closest and best example of a big galaxy in the final stages of a violent merger that is also in the process of shedding its cocoon and revealing a very energetic central quasar.”

“The energy involved is sufficient to sweep away matter from the galaxy,” adds Rupke. “The fireworks of new star formation and black hole feeding are coming to an end as a result of this outflow.”

Outflows in such galaxies have been observed before, but none sufficiently powerful to account for this predicted and fundamental aspect of galaxy evolution. The Gemini observations provide the first clear evidence for outflows powerful enough to support the process necessary to starve the galactic black hole and quench star formation.

The Gemini Observatory consists of two 8.1-meter diameter optical/infrared telescopes located in Chile and Hawaii. Gemini was built and is operated by a partnership of seven countries including the United States, United Kingdom, Canada, Chile, Australia, Brazil and Argentina.

The research was completed with support from the U.S. National Science Foundation, and its results will be published in the March 10 issue of The Astrophysical Journal Letters.

Click here to view the The Gemini Observatory news release.

photo courtesy of The Gemini Observatory


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