Philosophical Society of Washington

Long, Fast, and Multicolor Fireworks from the Center of Galaxies

Rita M. Sambruna
George Mason University & Goddard Space Flight Center


2204th Meeting Abstract
Friday, March 24, 2006 at 8:15 PM

Centaurus A Jet - Credits: X-ray: NASA/CXC/Bristol U./M. Hardcastle et al.; Radio: NRAO/VLA/Bristol U./M. Hardcastle

Abstract:

Relativistic ejecta (jets) from the center of radio galaxies are narrow, collimated streams of particles and energy extending from the inner parts of the optical galaxy to beyond its outskirts, at distances of millions of light years. Just like fireworks on the 4th of July, they shine at many colors across the electromagnetic spectrum, from radio to optical to X-ray wavelengths. Unlike in the case of fireworks, however, we still do not know what produces these long, fast, and multicolor structures. A billion solar mass, rapidly spinning black hole, a magnetic field, and an accretion disk seem to be essential ingredients for jet formation, but their relative importance still needs to be elucidated and quantified.

In this talk, I will review our current understanding of jet physics, focusing especially on recent observations with NASA's Chandra X-ray observatory and the Hubble Space Telescope. The superb angular resolution and sensitivity of these telescopes, coupled with ground-based radio observations, are providing ground-breaking clues on these enigmatic, yet fascinating, structures.

Rita Sambruna (with Reggie the Parrot)

About the Author:

Rita M. Sambruna has a PhD in Astrophysics from the International School of Advanced Studies in Trieste, Italy. From 2000 to 2005, she was member of the Faculty in the Department of Physics and Astronomy at George Mason University, and the Clare Boothe Luce Professor of Astrophysics. Currently, Dr. Sambruna is a senior Astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, MD, where she continues her research on active galactic nuclei and contributes to the upcoming Gamma Ray Large Area Space Telescope (GLAST) mission. To be launched in September 2007, GLAST will provide a sensitive survey of the sky at gamma-rays, unraveling current mysteries and discovering new ones. Rita lives in Clifton VA with her husband, five parrots, and two horses.


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