Keck Women Sharpen Our View of the Heavens
Atmospheric turbulence causes stars to twinkle and blurs cosmic images making it difficult for astronomers to know if they are looking at one object or two, or even more. This turbulence trips up even the largest telescopes, including the twin Kecks.
Veteran observers Andrea Ghez of the University of California, Los Angeles and Claire Max of the University of California Santa Cruz (UCSC), however, have, respectively advanced and pioneered techniques to make the stars stop twinkling — at least from Keck’s perspective. For this and other work, Ghez has been named a MacArthur Genius, and Max has earned Princeton’s Madison Medal.
Andrea Ghez gets animated as she discusses black holes during her 2006 talk, which was part of Keck’s special Evenings with Astronomers series. Credit: Sarah Anderson, WMKO.
Ghez was inducted into the MacArthur Fellows Program in September 2008. The program encourages writers, scientists, artists, social scientists, humanists, teachers, entrepreneurs and others of outstanding talent to pursue their own creative, intellectual and professional goals. Ghez has spent almost a decade exploiting two techniques, speckle imaging, which digitally combines very short telescopic exposures, and adaptive optics, which corrects for atmospheric turbulence to map the movement of a group of stars.
These stars sit in the Sagittarius constellation near the center of our Milky Way galaxy. From her team’s observations, Ghez discovered that some of the stars orbit the Galactic Center at velocities that are fractions of the speed of light. The stars’ motions provide the strongest evidence for the theory that a supermassive black hole sits in the center of the Milky Way.
“The study of the black hole at the Galactic Center by Dr. Ghez is clearly one of the most impactful results that Keck Observatory has produced,” says Taft Armandroff, director of the Observatory. “To me, this work underscores the discovery potential of adaptive optics and observational programs spanning many years. Dr. Ghez’s award is well deserved.”
Winning the fellowship will allow Ghez to take more risks and pursue new ideas and areas in her research, she says. One of her ideas is to detect dark matter at the center of the Milky Way. She is also interested in studying the center of globular clusters to look for the elusive intermediate mass black hole and in studying the center of other galaxies to understand star formation in extreme environments outside our galaxy.
But, Ghez says, “right now there is still so very much to do at the center of our galaxy.” She is now focusing her research on understanding how the galaxy’s central black hole interacts with the stars, gas and dust that surround it.
Watch as Ghez explains why she chose UCLA and why she loves to use the Keck telescopes. Courtesy of UCLA.
Same ‘star’, different picture
Claire Max discusses adaptive optics during her 2007 Evenings with Astronomers lecture. Credit: Sarah Anderson, WMKO.
Claire Max also makes ground-based telescopes see more clearly with adaptive optics. She is a co-inventor of the laser guide star adaptive optics systems used for astronomical research. For her work in this field, and her study of plasma physics, astronomy and astronomical instrumentation, Princeton University has honored Max with the 2009 James Madison Medal.
Early in her career, Max studied laser fusion at Lawrence Livermore National Laboratory, where she focused on laser-plasma interactions. Now, she directs the Center for Adaptive Optics, which is headquartered at UCSC. For her personal research, Max uses adaptive optics to study merging black holes at the centers of galaxies.
“Without Max’s leadership in implementing adaptive optics at Keck, many of our greatest contributions would not have happened. We join Princeton University in taking pride in such an impactful scientist,” Armandroff says.
Max earned her PhD from Princeton in 1972. The Association of Princeton Graduate Alumni awards the Madison Medal each year to a graduate student alumnus who has had a distinguished career, advanced the cause of graduate education or achieved an outstanding record of public service. Max is the first woman to receive the award, which is named for the fourth US president who many consider to be Princeton’s first graduate student. She received her medal and delivered an address during Princeton’s Alumni Day on Feb. 21, 2009. 