Cornell astronomers have developed a groundbreaking instrument, the Tomographic Ionized-carbon Mapping Experiment (TIME), which promises to revolutionize our understanding of the early universe. TIME offers a unique approach to studying the formation of early galaxies by measuring the combined glow from vast numbers of galaxies, rather than attempting to isolate individual galaxies. This method is akin to observing the overall brightness of a city from space, rather than counting individual streetlights.
Selina F. Yang, a doctoral student in physics, explains that TIME's spectrometer measures specific frequencies and patterns in the light emitted by molecules or atoms from distant galaxies. These patterns act as unique barcodes, allowing scientists to estimate the presence and distribution of molecules and atoms across the universe. This is particularly crucial for studying early star formation, as certain molecules are closely tied to the environments where stars are born.
The instrument's initial observations focused on Sagittarius A, a well-known region at the center of the Milky Way galaxy. By studying this region, the researchers aimed to validate their technique, line-intensity mapping, and ensure the instrument's accuracy in measuring molecular gas at various redshifts. This calibration is essential for understanding observations of molecular gas at different distances and times in the universe.
Abigail Crites, assistant professor of physics and principal investigator of the project, has been developing TIME for a decade. She is one of the first scientists to use line-intensity mapping to explore the early universe, and her work has opened up new avenues for studying cosmic history. The researchers are particularly interested in probing two distinct eras of cosmic history: the epoch of reionization, when the first stars and galaxies began to form, and the era when galaxies were forming stars at their highest rate several billion years later.
To demonstrate TIME's capabilities, the researchers tested it on Sagittarius A, a target closer to home. By studying the center of our galaxy, they could verify their frequency-resolving capabilities and calibration techniques. This approach allowed them to ensure the instrument's accuracy in measuring molecular gas at redshift zero, which is essential for understanding observations of molecular gas at higher redshifts.
The team's next steps involve returning to the Arizona Radio Observatory to focus on the targets TIME is specifically designed for: sources with much fainter emissions than Sagittarius A. They will study the COSMOS field, a well-studied part of the sky containing galaxies at various distances from Earth. This will provide valuable insights into the formation and evolution of galaxies across the universe.
In conclusion, the development of TIME represents a significant advancement in our ability to study the early universe. By employing a novel approach to measuring the combined glow from galaxies, Cornell astronomers are paving the way for a deeper understanding of cosmic history and the formation of early galaxies. This technology has the potential to unlock new discoveries and shed light on the mysteries of the cosmos.
