Grad student wins astronomy achievement award

During the conference banquet of the American Astronomical Society's (AAS) winter meeting held Jan. 7, Hwihyun Kim, a graduate student in the School of Earth and Space Exploration at Arizona State University, was named the recipient of the prestigious Chambliss Astronomy Student Achievement Award.

Touted as one of the largest gatherings of astronomers, the semi-annual meetings of the AAS offer an opportunity to rub elbows with the stars - the world's foremost scientists in the field of astronomy, astrophysics and cosmology. Over 100 years old, the AAS group gathered in Long Beach, Calif. Jan. 4-8 and amidst this stellar gathering Kim's contribution did not go unnoticed.

"My officemate found out that I had won the gold medal of the Chambliss Student Achievement Award. He took a picture of the announcement on the notice board and showed me when I was in the session room listening to the talk," says Kim, who is focusing on observational cosmology, with particular interests in nearby dwarf galaxies and satellite galaxies in different cosmic environments.

The Chambliss Astronomy Student Achievement Award, which serves to recognize exemplary research by graduate students who present poster papers at the semi-annual AAS meetings, was awarded to her for her poster presentation titled: "Radial Change of Stellar Populations in the Extremely Metal-Poor Galaxy CGCG 269-049."

"I saw many good posters at the meeting," says Kim, originally from Seoul, South Korea. "I think I was confident and explained my results well when the judges came to my poster and asked me questions. I like talking to people about my research and I always get excited when I do. I'm guessing the judges saw that excitement too."

Using a well-thought out and intuitive lay-out, figures that clearly illustrated both the method of analysis used and her results, and concise, to-the-point text that avoided excessive use of jargon, Kim was able to successfully convey the results of her research to specialists in the field and lay-persons. "It is these qualities," says one of her advisors Rolf Jansen, an associate research professional in the School of Earth and Space Exploration, "that likely made her poster stand out among those of her peers. She is a promising young researcher in extragalactic observational astronomy and cosmology, who also has a strong interest in teaching and public outreach."

Much of the current state-of-the-art observational cosmology deals with the farthest reaches and earliest epochs of the Universe. These can be investigated directly - with considerable difficulty - or indirectly, using "stellar archeology" in galaxies that are nearby enough to resolve into their individual stars using the Hubble Space Telescope. The indirect method works because the stars that make up a galaxy form a fossil record of the circumstances when they were formed.

Kim's research focuses on doing just that in very small nearby galaxies, in satellites of large massive galaxies and in extremely metal-poor free-floating dwarf galaxies. Her work is based on a detailed analysis of the colors and brightness of thousands of individual stars resolved in Hubble Space Telescope (Advanced Camera for Surveys/High Resolution Channel) images obtained by ASU alumnus Michael Corbin (U.S. Naval Observatory). Kim's doctoral dissertation (defense in 2010) aims to confront existing numerical simulations and theory of galaxy assembly with observational data.

"Reducing, analyzing and modeling these multi-color images was a very painstaking job. The galaxy is so compact that even in these highest resolution Hubble images, its young star clusters and its older stars are just like two swarms of differently-colored bees that are partially mixed," says Rogier Windhorst, professor in the school and advisor to Kim. "But she disentangled both and made sense out of them. We now know that this galaxy formed its first stars over 5 billion years ago, and then had a spontaneous burst of star-formation only about 100-200 million years ago."

"Professor Windhorst always encourages and supports his students to attend meetings and conferences such as AAS," says Kim. "If he wouldn't have encouraged me to go to the AAS meeting this time, it would have not happened to me."

Kim follows a proud tradition of recognition of students in the School of Earth and Space Exploration and the department of physics, both in ASU's College of Liberal Arts and Sciences. Amber Straughn, presently a postdoctoral fellow at NASA/Goddard Space Flight Center, received the award in 2006, and Russell Ryan (presently a postdoctoral scholar at UC Davis) and Nimish Hathi (presently a postdoctoral scholar at UC Riverside) each received honorable mention.