Charles Townes

What is Happening in the Center of our Galaxy?

Wednesday, 28 June 2000
15:30 - 16:00 CEST


The center of our own galaxy represents an important laboratory because it is closer than any other galactic center, is a very active region. It is obscured by surrounding dust clouds, but recently it has been successfully and intensively examined by microwaves, infared, and x-rays which penetrate the dust. Surrounding the center there are clouds of dust and molecules. Somewhat closer there are atomic clouds, and within approximately 2.5 light years, there is ionized material circulating around the center. Characteristics of materials surrounding the center indicate violent activity within the last 100,000 years. In addition, there are a rather large number of unusual stars near the center, including the brightest star ever discovered. At the very center there is an unusual object emitting intense microwaves which evidence shows rather clearly is a black hole of mass about 3*106 times the solar mass. This is demonstrated in part by the gas rapidly moving around the large mass, but recently most clearly by infrared imaging of nearby atars, and demonstration of their rapid motion due to the strong gravitational field. Although we have much information about this black hole and material surrounding it, radiation from this central object is not yet understood - it is much less than expected. This is an interesting laboratory where astronomical study and discovery continues.

Related Laureates