AS102 Study Guide - Quiz Guide: W. M. Keck Observatory, Iras, Milky Way
Document Summary
Finally, the latest word on galactic evolution is summed up nicely in this 3. 7-minute video from spacerip. After studying hundreds of galaxies using both the keck telescopes (hawaii) and the hubble space telescope astronomers have unearthed an unexpected pattern of galaxy evolution. Our own milky way galaxy is a pretty pedestrian spiral galaxy, steadily forming new stars at a rate of about five per year. However, other galaxies form new stars at a prodigious rate, over 100 per year. The result of such a high birth rate is that such galaxies will use up all the interstellar gas in a relatively short time (about 200 million years). They emit much of their radiation in the infrared part of the spectrum and thus, are not visible from the surface of the. Earth (because our atmosphere filters out infrared light). It was only when the iras (infrared astronomy satellite) was launched in 1983 that we became aware of such galaxies.
