Galactic Cannibals: A Free Public Presentation on 20 November 2003
A free presentation titled "Galactic Cannibals" will be given at 7:30 p.m. on Thursday 20 November in 100 Thomas Building on the Penn State University Park Campus by Christopher Palma, a lecturer and outreach fellow in the Eberly College of Science Department of Astronomy and Astrophysics. This event is part of the 2003-2004 Friedman Public Lecture Series in Astronomy.
Palma will present the latest images of galaxies eating other galaxies from the Hubble Space Telescope and ground-based telescopes, including proof that our own Milky Way Galaxy is chewing up its nearest neighbors. "When two galaxies collide, many of the billions of stars in each galaxy get flung out into space, forming brilliant streamers or tails," Palma says. He adds, "the Hubble Space Telescope has captured beautiful images of some famous galactic cannibals, including the Antennae, the Mice and Centaurus A, the quasar nearest to Earth. Palma's group has also studied cases where several members of a group of galaxies, such as Stephan's Quintet, participate in a "galactic feeding frenzy."
In many ways, astronomers find it is harder to study our own Milky Way Galaxy than to observe galaxies millions of light years away because we are embedded in a sea of nearby stars that screen us from observing the overall extent of our Galactic home. "It's like trying to see the distant headlights from oncoming cars in a thick fog," explains Palma. Nevertheless, Palma and his colleagues have used a few clever techniques for clearing up the foreground fog, which have revealed that the Milky Way is almost finished consuming a small galaxy that recently was discovered in the constellation Sagittarius.
Palma, who is a Penn State alumnus, returned to campus in 2001 after completing a Ph.D. in Astronomy at the University of Virginia. He is currently a lecturer in the Department of Astronomy and Astrophysics, and he is the first person to hold the title of "Outreach Fellow" in the Eberly College of Science. Palma spends much of his time giving astronomy presentations to students from kindergarten through 12th grade, working with science teachers during workshops, presenting planetarium shows, and assisting visitors with stargazing from Penn State's rooftop observatory on Davey Laboratory. He has been a guest astronomy expert on a radio talk show in Virginia, and his research has been featured on CNN.com and on the Astronomy Picture of the Day website.
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