Astronomers discover earliest 'barred' spiral galaxy from 11.5 billion years ago

Researchers led by Daniel Ivanov at the University of Pittsburgh may have uncovered the earliest known barred spiral galaxy. The findings, presented at the American Astronomical Society’s 247th meeting on January 8, identify the galaxy as COSMOS-74706.

The newly discovered barred spiral galaxy formation dates back approximately 11.5 billion years. This means it developed its unique structure just 2 billion years after the Big Bang.

A key characteristic of the discovered galaxy, like the Milky Way, is a linear structure of gas and stars, a “bar” that cuts across its center. This bar is crucial for galactic evolution because it channels gas inward. This process, in turn, fuels supermassive black holes.

The finding of an ancient barred spiral, therefore, provides vital clues about our own galaxy’s formation.

While previous studies have claimed to identify ancient barred galaxies, Ivanov’s team distinguishes their finding, COSMOS-74706, through confirmed precision.

Earlier candidates often depended on less dependable analysis or were skewed by gravitational lensing. However, COSMOS-74706 was verified using spectroscopy. This led Ivanov to describe it as the “highest redshift, spectroscopically confirmed, unlensed barred spiral galaxy.” This discovery challenges the timeline of galactic structural formation.

NASA previously believed that barred galaxies were rare in the early universe. Their numbers remained very small, even 7 billion years ago. The discovery of such a developed structure from that epoch suggests that some galaxies matured and stabilized more quickly than conventional models anticipated.