Distinguished Lecture Series in Physics

A New Revolution in Astronomy 400 Years After Galileo

We live in a new heroic period of astronomical discoveries comparable for its impact on human understanding of the universe to that which occurred from Copernicus to Newton. New observatories in space and on the ground have opened up the study of the entire range of wavelengths emitted by celestial bodies reaching Earth from the farthest reaches of the cosmos. These studies have revealed the crucial role played by explosive events in the formation and development of the structures we now see. They also reveal the prevalence of unknown forms of matter and energy in our universe, where normal matter made of nucleons provides only 3% of the total. These discoveries require new physics, just as it happened 400 years ago.

X-Ray Astronomy 2009

It has been 10 years since the launch of the Chandra X-Ray Observatory, still in full operation today. Chandra has reached greater sensitivity and finer angular resolution than any other X-ray astronomy mission to date. Its sensitivity is some 10 billion times greater than the one necessary to discover the first X-ray star Sco X-1 in 1962. Its angular resolution of 0.5 arc seconds is comparable to that of ground based optical telescopes.

X-ray observations play a unique role in the study of some of the objects of greatest current astrophysical interest and their grasp rivals that available with the most powerful observatories in space and on the ground at all wavelengths. The use of Chandra in studying baby stars, supernovas, AGNs, the X-ray background, clusters of galaxies, dark matter and dark energy will be described. Some comments about the future will follow.