Cornell astronomers have developed a groundbreaking instrument called TIME (Tomographic Ionized-carbon Mapping Experiment) that promises to revolutionize our understanding of the universe's earliest galaxies. This innovative tool takes a unique approach by measuring the combined glow from numerous galaxies rather than attempting to isolate individual galaxies. By doing so, it provides a more comprehensive view of the universe's history and evolution.
Selina F. Yang, a doctoral student in physics, explains this technique as akin to observing a city's lights from space. Instead of counting individual streetlights, TIME measures the overall brightness of an entire city, allowing for a more holistic understanding of the cosmic landscape. This method is particularly useful for studying the faint and distant galaxies that traditional telescopes struggle to observe.
The instrument's first observations, published in the Astrophysical Journal, focused on Sagittarius A, a well-known region at the center of the Milky Way galaxy. These observations confirm that TIME is ready to map future targets at the Arizona Radio Observatory's 12-meter telescope. The study also validates a technique called line-intensity mapping, which will be utilized in new instruments on other telescopes, including the Cornell-led Fred Young Submillimeter Telescope.
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. This technique involves gathering light from a large portion of the sky and analyzing the specific frequencies and patterns emitted by molecules or atoms from faint galaxies. By translating these distinctive 'barcodes' into an estimation of molecular and atomic concentration, researchers can gain valuable insights into early star formation.
TIME aims to probe two distinct eras of cosmic history. Emissions from ionized carbon can study galaxies during the epoch of reionization, when the first stars and galaxies illuminated the universe one billion years after the Big Bang. Emissions from carbon monoxide provide insights into the era when galaxies were forming stars at their highest rate, several billion years later.
To prove TIME's capabilities, the researchers tested it on Sagittarius A, the center of our galaxy. This allowed them to verify their frequency-resolving capabilities and calibration techniques. By comparing observations of molecular gas at redshift two (light traveling towards Earth 2.5 billion years ago) with measurements at redshift zero, they ensured the instrument's accuracy.
Cosmologists are excited about TIME's potential to probe galaxy formation and the evolution of matter and structure across the universe. Line-intensity mapping, once a fringe idea, is now gaining popularity. By tracing the population of galaxies, researchers can trace cosmological structure, offering a deeper understanding of the universe's past and present.
In conclusion, TIME represents a significant advancement in our ability to study the universe's earliest galaxies. Its unique approach and validation through observations of Sagittarius A demonstrate its potential to unlock new insights into the cosmos. As the researchers continue their work, we can anticipate further discoveries that will shape our understanding of the universe's fascinating history.
