Fall 2014

The Odd Couple: Quasars & Black Holes

Scott D. Tremaine

Quasars emit more energy than any other object in the universe, yet are not much bigger than our solar system. Quasars are powered by giant black holes of up to ten billion (1010) times the mass of the sun. Their enormous luminosities are the result of frictional forces acting upon matter as it spirals toward the black hole, heating the gas until it glows. We also believe that black holes of one million to ten billion solar masses – dead quasars – are present at the centers of most galaxies, including our own. The mass of the central black hole appears to be closely related to other properties of its host galaxy, such as the total mass in stars, but the origin of this relation and the role that black holes play in the formation of galaxies are still mysteries.

SCOTT TREMAINE, a Foreign Honorary Member of the American Academy since 1992, is the Richard Black Professor in the School of Natural Sciences at the Institute for Advanced Study and the Charles A. Young Professor of Astronomy on the Class of 1897 Foundation, Emeritus at Princeton University. His research interests are centered on astrophysical dynamics, including planets, small bodies in the solar system, galaxies, black holes, and galactic nuclei. His work is published in such journals as The Astrophysical Journal and Monthly Notices of the Royal Astronomical Society. With James Binney, he is the author of the graduate textbook Galactic Dynamics.

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