Cornell astronomers have developed a groundbreaking instrument, TIME, that promises to revolutionize our understanding of the early universe. This innovative tool allows scientists to peer into the formation of the first galaxies, which are too distant and faint to be observed individually with traditional telescopes. By measuring the combined glow from countless galaxies, TIME offers a unique perspective on cosmic history, akin to observing the overall brightness of a city from space rather than counting individual streetlights.
The instrument's capabilities are showcased in a recent study published in the Astrophysical Journal, where researchers report on the first observations made during the 2021-22 season at the Arizona Radio Observatory's 12-meter telescope. These initial tests focused on Sagittarius A, a well-known region at the center of the Milky Way galaxy, and confirmed TIME's readiness for future mapping missions.
TIME employs a technique called line-intensity mapping, which is set to be utilized in new instruments on other telescopes, including the Cornell-led Fred Young Submillimeter Telescope. This method gathers light from a vast portion of the sky, enabling the spectrometer to measure specific frequencies and patterns emitted by molecules or atoms from distant galaxies. These patterns act as unique identifiers, akin to barcodes, allowing scientists to estimate the presence and distribution of various molecules and atoms across the universe.
The research team aims to study two distinct eras of cosmic history. Emissions from ionized carbon will be used to explore the epoch of reionization, when the first stars and galaxies illuminated the universe just one billion years after the Big Bang. Emissions from carbon monoxide will provide insights into the era when galaxies were forming stars at their peak rate, several billion years later.
To validate TIME's capabilities, the researchers conducted tests on Sagittarius A, a closer target that allowed them to verify their frequency-resolving abilities and calibration techniques. This approach ensures that the instrument can accurately measure molecular gas at various redshifts, including redshift zero, which corresponds to the present day.
The development of TIME represents a significant advancement in cosmology, offering a novel approach to probing galaxy formation and the evolution of matter and structure across the universe. As the researchers continue their work, they aim to explore the implications of these findings for cosmology, emphasizing the importance of tracing the population of galaxies to understand the underlying cosmological structure.
