We're going to stray from the traditional format of this page, and feature a faculty member . I'd also like to welcome a new writer to the SPECTRUM, Chad Vicenik.

The man behind the ponytail: Dr. Karl Gebhardt

There is a fairly good chance that if you're an astronomy major, you know Karl Gebhardt. Dr. Gebhardt is the undergraduate faculty advisor, so you have to go to him to remove those pesky advising bars when you go to register for your classes. He also runs the freshman seminar course, AST 104, and teaches a section of AST 301.

However, there’s more to Karl Gebhardt than checking the schedules of students. He is heavily involved in research and recently published a paper about the discovery of super massive black holes in the center of globular clusters.

Karl Gebhardt attended the Michigan State University in 1986 and graduated with his Masters four years later. He started his teaching career there, beginning as a teaching assistant, later winning the Best Teaching Assistant Award in 1990. He continued on to Rutgers University in New Jersey, and graduated with his doctorate in 1994.

He initially attended graduate school in physics because he was interested in string theory. But, he was turned off when he noticed that most of the work involved collaborations of 100 or so scientists, who would spend their time configuring detectors for particle accelerators. "Astronomy," he says, "is still a field where an individual can make an impact."

As far as research goes, Karl is interested in numerous topics. One of his principle interests is the dynamics of globular clusters. In his thesis, he developed a method of using the Imaging Fabry-Perot Spectrophotometer to determine the velocities of several hundred stars using only a few hours of observation time.

He's currently furthering this work by using the velocity measurements taken from the FP to calculate mass density profiles of globular clusters. Another result of this method is a velocity map of the cluster, which Karl uses to study the rotation rates. Globular clusters are a roughly spherical group of stars. The old idea was that they didn't rotate because things that rotate tend to flatten out; however, Gebhardt has discovered that globular clusters do indeed rotate. In fact, this research led to the recent discovery of a black hole in the center of a globular cluster.

What Karl says he's most interested in is the evolution of elliptical galaxies. He has been taking data from the Keck Telescope in Hawaii and trying to find the mass of the galaxies as a function of cosmic time. As you look at higher redshifts, the farther back in time you look. Once the mass of the galaxy is determined, Karl can calculate the age of that galaxy. Essentially, he is trying figure out the birthday of these galaxies, and he's found that elliptical galaxies formed at a time corresponding with a redshift of 2, or about 4 or 5 billion years ago, contrary to the old idea that galaxies formed in an era corresponding to a redshift of 3, 4 or 5.

Karl became the undergraduate faculty advisor this semester and will remain so for at least two years. He has been working with Greg Shields to create a Bachelor of Science for the Astronomy department, which was recently passed by the faculty and sent to the administration for approval. Other goals for the department include creating a few more courses and having the existing upper division courses be taught more often. Most importantly, though, he says, is to get the undergrads involved in research. He would like to see a program where undergrads could go out to McDonald Observatory and spend time observing.

Be sure to check out the article by Phill detailing Karl Gebhardt's recent discovery of a black hole in the center of a globular cluster featured in this edition of the Spectrum.