The inauguration of the Fred Young Submillimeter Telescope (FYST) at the summit of Cerro Chajnantor in Chile's Atacama Desert marks a significant milestone in astronomy. This telescope, a product of international collaboration, has been three decades in the making and is designed to observe the universe in a unique way. The altitude of 18,400 feet above sea level is no accident; it's strategically chosen to take advantage of the thin, dry air in the Atacama Desert, which allows for the observation of submillimeter light, a crucial part of the electromagnetic spectrum. This light, with wavelengths shorter than a millimetre, is absorbed by water vapour at lower altitudes, making the high-altitude location ideal for FYST's purpose.
What sets FYST apart is its innovative Crossed-Dragone optical design, which enables it to capture exceptionally clean images across a wide field. This design, combined with its ability to rapidly sweep large areas of the sky, makes FYST more akin to a celestial movie camera than a traditional telescope. Its primary instrument, Prime Cam, is equipped with over 100,000 superconducting detectors, enabling it to map the sky at a speed ten times faster than any previous submillimeter observatory. This capability allows FYST to create deep, wide surveys of the sky in a part of the spectrum that has never been systematically filmed before.
The science agenda of FYST is equally ambitious. It aims to probe the cosmic microwave background in search of the fingerprint of primordial gravitational waves predicted by inflation theory. It will map galaxy clusters across the history of the universe, trace the formation of stars hidden behind dense clouds of dust, and study the epoch of reionisation. Submillimeter light, passing straight through dust that blocks visible wavelengths, reveals structures that are otherwise invisible, providing a unique perspective on the universe.
The construction of FYST is a testament to the dedication and hard work of the international team behind the project. Built in Germany from a specially formulated steel alloy called Invar, which barely expands or contracts with temperature changes, the telescope was then disassembled, shipped across the Atlantic, and trucked 300 miles across the Andes before being reassembled at the summit. This journey, spanning over three decades, is a remarkable achievement in itself, and when FYST begins operations, it will offer a view of the universe that no telescope has provided before, repaying the team's patience and efforts with groundbreaking discoveries.
