Scientists have detected seismic ripples in the ancient galactic disk of BRI 1335-0417, providing a new perspective on the formation of this far-off galaxy and shedding light on the origins of our Milky Way. BRI 1335-0417, at over 12 billion years old, stands as the oldest and most distant spiral galaxy known in the universe. The advanced capabilities of the ALMA telescope enabled researchers, led by Dr. Takafumi Tsukui, to closely examine this ancient galaxy.
The team not only captured the gas motion around BRI 1335-0417 but also observed the formation of a seismic wave—a groundbreaking occurrence for such early galaxies. Dr. Tsukui emphasized their interest in understanding how gas moves within the galaxy, as it plays a crucial role in star formation. Gas dynamics offer valuable insights into a galaxy’s star-forming processes, and this study marked the first observation of a seismic wave in a galaxy of this era.
The galaxy’s disk, a flat expanse of rotating stars, gas, and dust, exhibited motions resembling ripples on a pond. Dr. Tsukui explained that the vertically oscillating disk motion resulted from external sources, such as new gas influx or interactions with smaller galaxies. Both scenarios could supply the galaxy with the necessary fuel for star formation. Furthermore, the study unveiled a bar-like structure in the disk—a distant and unique finding.
The distance of BRI 1335-0417 means that the light reaching Earth provides a glimpse into the galaxy’s early days when the universe was only 10% of its current age. Despite having a mass similar to the Milky Way, BRI 1335-0417 exhibits a star formation rate hundreds of times faster than modern galaxies. Co-author Associate Professor Emily Wisnioski highlighted the need to understand how gas is supplied to sustain such rapid star formation.
The rarity of spiral structures in the early universe adds complexity to their formation, and this study contributes crucial information to unravel these mysteries. While direct observation of the galaxy’s evolution is impossible, the use of computer simulations complements these snapshots, helping scientists piece together the dynamic growth story of this young galaxy.
