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MAUNAKEA SKIES Astronomy Talk Series - Galaxy Evolution and Ecology

  • ʻImiloa Astronomy Center 600 Imiloa Place Hilo, HI, 96720 United States (map)

Join Dr. Yusei Koyama, Subaru Telescope’s Assistant Professor, in his presentation on Friday, June 21st at ‘Imiloa’s planetarium, 7pm, where he will discuss recent efforts to identify the rich diversity of galaxy clusters in the early universe and to discover their origins.

Understanding the history of galaxy evolution is one of the most fundamental studies for human beings, because we are the residents of our galaxy. Galaxies are very basic “species” living in the universe, but the natures of galaxies in the present-day universe are really diverse. Some galaxies show blue colors with prominent spiral arms, while some other galaxies show red colors with more smooth, elliptical morphologies. Why are the natures of galaxies so diverse? An interesting hint is brought by studying the “ecology” of galaxies. Recent observations revealed that – like human beings – the nature of galaxies living in the crowded regions (“big cities”) and those living in less dense environments (“country-side”) is totally different. The next big challenge for astronomers is to identify the origin of such environmental trends, by observing the site of galaxy assembly in the past universe.

Observations of distant galaxies directly tells the history of galaxy formation and allow astronomers to deliver the nature of galaxies in the past. Koyama will also introduce Subaru Telescope’s new instrumentation program, ULTIMATE, which delivers sharp image quality over a wide area on the sky assisted by adaptive optics. This will be a new instrumentation program for Subaru Telescope’s observation of the deep universe. 

Born in Japan, Koyama received his Ph.D. in astronomy at the University of Tokyo in 2011. He proceeded to do his first postdoctoral research at Durham University in England, where he stayed for about 2 years, and then moved back in Japan in 2013 to start his second postdoc at JAXA (Japanese space agency, similar to NASA in the United States). Koyama moved to Subaru Telescope in 2015 as a faculty member of National Astronomical Observatory of Japan. His main research field is galaxy formation and evolution in the context of structure formation of the universe. Koyama is also leading the ULTIMATE-Subaru project.

Sharing Hawai‘i’s legacy of exploration, ‘Imiloa Astronomy Center is a world-class center for informal science education located on the University of Hawai‘i at Hilo campus. Its centerpiece is a 12,000 sq. ft. exhibit hall, showcasing science and Hawaiian culture as parallel journeys of human exploration guided by the light of the stars. The visitor experience is amplified with presentations using ‘Imiloa’s full dome planetarium and 9 acres of native landscape gardens. The Center welcomes more than 100,000 visitors each year, including 12,000+ schoolchildren on guided field trips and other educational programs. ‘Imiloa is located at 600 ‘Imiloa Place in Hilo, off of Komohana and Nowelo Streets at the UH Hilo Science and Technology Park. For more information, visit or call 808-932-8901.

Earlier Event: June 14
Later Event: June 28