As the first scientific results from the new Fred Young Submillimeter Telescope (FYST) draw nearer, enthusiasm among the scientists readying the telescope climbs ever higher.
“FYST will become the most powerful telescope in its class, facilitating important science and enlightened student involvement for many years to come,” donor and scientific advisor Fred Young '64, M.Eng '66 said at a September event celebrating the completion of the telescope’s construction.
The first observations will focus on the planets in the solar system to calibrate the instruments. Soon after will begin early science measurements of galaxy clusters, the largest gravitationally bound objects in the universe, according to Michael Niemack, professor of physics and astronomy (A&S) and leader of the Prime-Cam team.
Prime-Cam and mini-CHAI (led by University of Cologne) are the first scientific instruments being installed on FYST. Prime-Cam has seven instrument modules with three detector arrays per module and fits thousands of detectors on a single silicon wafer. The tens of thousands of detectors make Prime-Cam the largest submillimeter instrument ever built.
The Prime-Cam instrument and supporting equipment were shipped from Cornell to Chile in June in two 40-foot shipping containers. The shipment included a cleanroom, which is particularly important for keeping dirt off the sensitive Prime-Cam detectors and optics despite FYST’s windy location. The telescope is at extreme altitude, 18,400 feet above sea level, near the summit of Cerro Chajnantor in Chile’s Parque Astronómico Atacama (Atacama Astronomical Park) in the Atacama Desert. The high, extremely dry location is necessary to detect the submillimeter light for which the telescope is designed.
Since Prime-Cam’s arrival at the site on July 30, the team has been busy unpacking its components and getting ready for installation. The test fitting began in August and the installation of Prime-Cam on FYST will follow FYST commissioning in October. According to Niemack, the instrument will take about four weeks to install, then two weeks to cool it down to the -273 Celsius temperature needed for the detectors to achieve their design sensitivity and prevent Prime-Cam’s own thermal signature from obscuring the very faint submillimeter signals it is designed to detect.
“Our goals are to pursue exciting, unique science using a large fraction of the FYST field of view,” Niemack said. “Prime-Cam will also serve as a testbed for next generation technologies,” such as the new spectroscopy module being designed by Abigail Crites, assistant professor of astronomy and physics and Fred Young Faculty Fellow (A&S).
FYST’s second initial scientific instrument, mini-CHAI, a precursor of the full-size CCAT Heterodyne Array Instrument (CHAI), is en route to Chile and should arrive mid-November, according to scientists at the University of Cologne who designed and built the instrument. CHAI is a high-resolution spectrometer that will enable scientists to study the cycle of interstellar matter in the Milky Way and nearby galaxies.
“With the technology used in CHAI astronomers can conduct large-scale surveys of the spectral fingerprint of atoms and molecules,” said Marc Merten, University of Cologne research scientist.
“The unprecedented sensitivity due to the combination of CHAI and the unique telescope and observing site even allow us to measure the profiles of spectral lines in the universe, including the same we will probe in Line-Intensity Mapping (LIM) observations," said Dominik Riechers, professor for experimental astrophysics at the University of Cologne in Germany and member of the CCAT Observatory, Inc. board of directors. (LIM maps the large-scale distribution of matter by measuring aggregate emission from a specific spectral line.) "Moreover, mini-CHAI in particular will play a central role in the calibration of the telescope to enable the first precise astronomical measurements with both instruments."
Observations of emission from atomic carbon, carbon monoxide and other chemical species reveal the conditions, kinematics and dynamics in star-forming regions on unprecedented scales from dense cores in the Milky Way to discs of nearby galaxies.
The FYST science team has been enhanced with the addition of a new postdoctoral fellow, Ankur Dev. He’ll be the first postdoc on the project working specifically on data analysis, according to project scientist Nicholas Battaglia, associate professor of astronomy (A&S). Dev will develop data reduction workflows, detector timestream analysis pipelines and map-making methods for the continuum and spectrometer cameras of the Prime-Cam instrument, with a particular focus on Line-Intensity Mapping observations.
The science team meets weekly to discuss the science the telescope will enable. “We’ve been running simulations of observations to prepare for unknown things and understand the intricacies of the data, as well as testing new scanning techniques and the new detectors,” said Battaglia. “Our hope is that when we start making observations, we are prepared to quickly make beautiful images of the sub-millimeter sky.”
The team has laid out a list of surveys it will undertake on important scientific questions. These include:
- The Cosmic Microwave Background (CMB) Survey will take measurements of the Cosmic Microwave Background (the universe’s oldest light) and study sources of interference in the CMB, such as searching for faint signals left when this ancient light scattered off the first atoms. As a “baby picture” of the universe, CMB can provide information on the fundamental parameters governing our universe.
- The Sunyaev-Zel'dovich (SZ) Survey will use observations of hot gas surrounding galaxy clusters to better understand how galaxies and clusters, the largest structures in the universe, form and evolve.
- The Line-Intensity Mapping (LIM) Survey will study the Epoch of Reionization, when the first stars and galaxies lit up the universe, by measuring the combined glow of carbon monoxide and ionized carbon across vast cosmic distances.
- The Cosmic Infrared Background (CIB) Survey will trace galaxy formation from the first billion years to Cosmic Noon.
- The Galactic Survey will map the Milky Way's magnetic fields and study how they influence the gas and dust from which stars are born. FYST will enable scientists to map out magnetic fields in much higher fidelity and with a better signal-to-noise ratio.
- The Transients Survey will scan the sky for sudden, short-lived flashes of invisible light with tiny wavelengths over a wide range of time scales.
“FYST and Prime-Cam provide ideal observations to remove dust emissions and potentially unveil gravitational waves from the very beginning of our universe,” Battaglia said.
FYST will also help untangle the mysteries about the dominant forms of energy in our universe, dark energy and dark matter, Niemack said.
Star formation is another scientific mystery FYST will help unravel. Many galaxies have dust that stores starlight and re-emits it at longer wavelengths. This happens in enough galaxies that if you use optical and near-infrared telescopes like JWST, you will only see a quarter of the star formation that happens across the universe, said Dongwoo Chung, assistant professor of astronomy (A&S), at their September talk at Cornell’s Friends of Astronomy Symposium.
“You need to survey in the infrared, in the wavelengths FYST will access, to capture the missing 75% at this high resolution,” they said.
Chung is also excited about interactions between the Cosmic Infrared Background and Line-Intensity Mapping science questions, especially as FYST acts as a platform for densely packed arrays of spectrometers replacing large gratings on other instruments. “This will be the equivalent of moving from vacuum tubes to transistors,” they said.
Studying dust will help answer even more scientific questions. In an online conversation with Cornell President Michael Kotlikoff and Niemack, Martha Haynes, Distinguished Professor of Arts and Sciences in Astronomy Emerita (A&S), said, “We also want to understand what molecules are out there in space. And since molecules in space like to form on dust grains, we want to understand the dust…if we want to understand the origin of life.”
The CCAT Observatory operates the Fred Young Submillimeter Telescope under a partnership of Cornell University, a German consortium consisting of the University of Köln, the University of Bonn and the Max Planck Institute for Astrophysics, a consortium of eight Canadian universities led by the University of Waterloo, and Duke University. CCAT operates in Chile under a cooperative agreement with the University of Chile and under the auspices of the Ministry of Foreign Affairs.
