Wednesday, July 29, 2009
First Light for Cosmic Web Imager
Back at the end of May Cosmic Web Imager, the newest instrument for the 200-inch telescope, got a test fit. Actually, back then it wasn't even built. Last night the finished instrument achieved first light.
The Cosmic Web Imager (CWI) was built to help astronomers explore the intergalactic medium. It will be used to map ultraviolet emissions from the low surface brightness universe and tell us where gas is located out between galaxies. Up until now, astronomers have had narrow keyhole-like views into the universe where they have been able to map intergalactic matter. By studying how the light from a distant quasar is affected as it passes through clouds of matter located between Earth and the quasar, astronomers have been able to map the location of these clouds, but only those in the same line of sight as a quasar. CWI should provide astronomers with a much richer view of where this material is and provide new insights on the formation of galaxies and the presence of dark matter.
The image above shows the new instrument mounted in the Hale Telescope's Cassegrain cage. Congratulations to Chris Martin and his team at Caltech for bringing this new instrument to life! They have 2 more nights of commisioning before the instrument returns again in October.