Eiichi Egami Colloquium Abstract (Jan 18, 2017)

Observing the Distant Universe through Powerful Gravitational Lenses in Space

The history of modern astronomy can be seen as the quest to achieve the best possible observational sensitivity by building larger and larger telescopes and more and more sensitive instruments. However, there is another effective way to improve the observational sensitivity. That is, to discover and study sources that are strongly magnified by the effects of gravitational lensing. Individual galaxies as well as clusters of galaxies in space would act as such gravitational lenses, and could amplify the brightnesses of background galaxies by a significant factor (up to ~100x in some exceptional cases), allowing us to see galaxies in the distant Universe that are inaccessible otherwise. In this talk, I will describe how gravitational lensing works in the context of observational astronomy, and will review a series of exciting discoveries/results that were made possible by the explosion of our observing capabilities in recent years. I will specifically highlight some results from our recent survey of distant lensed galaxies using the Herschel Space Observatory and from subsequent follow-up observations using other powerful observing facilities such as the Hubble Space Telescope and Atacama Large Millimeter/submillimeter Array (ALMA).