New Chilean Telescope Opens a Window on the Early Universe

Look to your left: red dirt and rocks. Look to your right: red dirt and rocks. The sky? Painfully clear. The air? Hard to breathe.  

It’s in this otherworldly landscape where Duke physicist Eve Vavagiakis and over a hundred other attendees celebrated the inauguration of the Fred Young Submillimeter Telescope (FYST), marking a major milestone for an international collaboration and promising new insights into some of the biggest questions in cosmology.  

Located on Cerro Chajnantor, a peak towering high in Chile’s Atacama Desert, 18,400 feet above sea level on the western side of the Andean Plateau, FYST is the flagship telescope of the Cornell University-led CCAT Observatory. The telescope will map large regions of the sky with unprecedented speed and sensitivity, helping researchers study everything from the formation of galaxies to dark matter and dark energy.  

Duke is the only U.S.-based institutional partner in the project outside of Cornell. 

Vavagiakis, an assistant professor of Physics and an alumna of Cornell, leads Duke’s contributions to Prime-Cam, FYST’s powerful first-light camera. Prime-Cam is designed to measure faint signals from across cosmic history, including light dating back to the universe’s earliest moments. 

These faint signals come in the form of submillimeter wavelengths of light, wavelengths not far from those of your microwave oven. Though that light is invisible to our human eyes, it can be detected by Prime-Cam atop FYST. 

But even the most advanced camera would fail to capture submillimeter light if its field of vision were clouded with interference, which comes in the form of something quite ubiquitous: water vapor.  

Water absorbs energy in the submillimeter range — that’s actually how your home microwave turns a bowl of congealed blob into delicious warm soup — making it undetectable. The solution? Put these cameras in environments that are bone dry and sit above much of the Earth’s atmosphere, such as Cerro Chajnantor.   

Those conditions will allow FYST to conduct what project leaders describe as a new kind of “celestial cinematography” — repeatedly surveying large portions of the sky to create time-resolved maps of the universe in wavelengths that have never before been observed this way. 

For Vavagiakis, the inauguration marks the culmination of years of work. During her Ph.D. at Cornell, she worked on Prime-Cam's cryomechanical systems — the hardware that allows the instrument to function at ultracold temperatures. Now, as Prime-Cam's receiver scientist, she helps oversee the camera's deployment and scientific operation. 

"It's really exciting to see Prime-Cam go from CAD rendering to science during my career," she said. "I designed much of the cryomechanical components of Prime-Cam during my Ph.D., and now I get to deploy the instrument on FYST with my group this year as Prime-Cam receiver scientist." 

The inauguration ceremony, held April 9 in Chile, brought together scientists, institutional leaders and collaborators from the United States, Canada, Germany and Chile. The event celebrated not only the completion of the telescope itself, but also the decades of international collaboration that made the project possible. 

 “It is the realization, through the incredible determination, foresight and vision of so many treasured partners, of a unique vision for an enterprise led by academic scientists,” said Cornell University President Michael I. Kotlikoff. “And it will carry the spirit of collaboration and cooperation that brought us to this moment forward, through new partnerships and new discoveries.”