A groundbreaking study of the ancient spiral galaxy, BRI 1335-0417, has been conducted using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope, revealing significant insights into the galactic formation process and shedding light on the early stages of the universe. With a staggering age of over 12 billion years, BRI 1335-0417 stands as the oldest and most distant known spiral galaxy in existence.
Dr. Takafumi Tsukui, the lead author of the study, emphasized the importance of ALMA’s advanced capabilities in scrutinizing this ancient galaxy in unprecedented detail. The primary focus of the investigation was to unravel the intricate dynamics of gas movement within BRI 1335-0417, a critical factor influencing star formation and providing crucial clues about a galaxy’s fueling mechanisms.
The observations not only captured the intricate dance of gas surrounding BRI 1335-0417 but also detected the formation of a seismic wave—a remarkable first for galaxies of this early epoch. The galactic disk, comprising a flat assembly of rotating stars, gas, and dust, exhibited a vertical oscillating motion akin to ripples spreading across a pond. This motion, as Dr. Tsukui explained, is likely induced by external influences, such as the influx of new gas into the galaxy or interactions with smaller neighboring galaxies.
Furthermore, the study unveiled a bar-like structure within the galactic disk, representing the most distant example of such a feature. Galactic bars can disrupt gas and channel it toward the central regions of a galaxy, influencing star formation processes. These findings collectively indicate the dynamic evolution of a young galaxy.
Due to its immense distance, the light from BRI 1335-0417 takes an extensive journey to reach Earth, offering a glimpse into the galaxy’s formative years when the universe was merely 10% of its current age. Despite its similarity in mass to the Milky Way, BRI 1335-0417 exhibits a star formation rate several hundred times faster than modern galaxies.
Associate Professor Emily Wisnioski, a co-author of the study, highlighted the galaxy’s rapid star formation and the need to understand the mechanisms supplying the necessary gas to sustain such intense activity. While direct observation of the galaxy’s evolution is impossible due to the nature of snapshots provided by telescopic observations, computer simulations can aid in reconstructing the story of BRI 1335-0417’s early existence, offering valuable insights into the cosmic processes shaping galaxies in the early universe.
Content from the Australian National University. Note: The content may have been edited for style and length.
Journal Reference:
- Takafumi Tsukui, Emily Wisnioski, Joss Bland-Hawthorn, Yifan Mai, Satoru Iguchi, Junichi Baba, Ken Freeman. Detecting a disc bending wave in a barred-spiral galaxy at redshift 4.4. Monthly Notices of the Royal Astronomical Society, 2024; 527 (3): 8941 DOI: 10.1093/mnras/stad3588