Towards an atacama large aperture submillimeter telescope
Observations of the sky at sub-millimeter and millimeter ((sub)mm) wavelengths have yielded transformational results in the study of the origin of chemical complexity, the birth of stars and planetary systems, the evolution of galaxies across cosmic times and the large-scale architecture of the Universe. The current generation of 10-meter class single-dish (sub)mm telescopes has opened a new window for astronomical discoveries, by revealing physical processes and components that are invisible at shorter wavelengths. These facilities, with interferometers used for detailed follow-ups, have enabled astrophysicists to go far beyond the biased ""optical/infrared"" view of the Universe, often prompting major revisions of theoretical models. 

However, it is now clear that these previous facilities will not be able to meet the challenges of 21st century Astrophysics. Indeed, the astronomical community worldwide has agreed that a transformational leap in discovery potential can only be enabled by a next generation, large aperture (50-meter diameter), single dish telescope operating at (sub)mm wavelengths. 

We hereby propose a design study for the Atacama Large Aperture Submillimeter Telescope (AtLAST). Our vision of AtLAST includes: a 50-m class dish, with high throughput and a field of view of two degrees, located at a high, dry site in the Atacama desert where the transparent atmosphere enables observations at frequencies up to the terahertz regime. We envision AtLAST as an international partnership operating a facility telescope, and we will explore ways to make the observatory fully powered by renewable energy. Such infrastructure will be unique in the landscape of current research facilities. Our project aims to obtain a comprehensive feasibility study and telescope design that take into account the technical, operational, and environmental challenges of such infrastructure, and that can achieve the transformational science goals defined by the community.

