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Secrets of the Cosmos

Black Holes and Galaxy Formation


Carnegie Mellon physics professor Tiziana Di Matteo is finding the answers to long-standing questions about black holes and how they help shape the galaxies.

For years, scientists have observed that the total mass of stars in today's galaxies corresponds directly to the size of a galaxy's black hole. But until now, no one could account for this observation. By incorporating Di Matteo's calculations for black hole dynamics into a computational model of galaxy formation, researchers have been able to piece together the evolution of galaxies more accurately.

"With these computations, we now see that black holes must have an enormous impact on the way galaxies form and evolve," said Di Matteo.

Her work was recently featured in Monster of the Milky Way, a NOVA documentary about black holes. Viewers were treated to stunning computer imagery as researchers revealed new insights into one of the most destructive objects of the universe.

Super-massive black holes, whose activities Di Matteo simulates as part of her research, lie at the heart of most, if not all, large galaxies. They are formed through the collision of galaxies drawn together by the pull of gravity, and once formed, these powerful giants consume all of the cosmic matter that surrounds them.

Could the black hole believed to lie at the center of our galaxy flare up and consume our entire galactic neighborhood?

"When our galaxy collides with the Andromeda galaxy, which has a black hole almost 10 times larger than our Milky Way's, their black holes will merge and all the gas and stars will be rearranged to form a giant new galaxy," explained Di Matteo.

While Di Matteo acknowledged a chance that our solar system might end up close enough to a new black hole to be swallowed up, she added, "we should only worry about this if we are planning to be around in 2 billion years' time"

Related Links: Astrophysics and Cosmology  |  Tiziana Di Matteo

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