ASTRONOMY
A recent discovery by astronomers reveals that seismic ripples have been detected in an ancient galactic disk
Astronomers have detected seismic waves in an ancient galaxy's disk, providing new insights into its formation and the origins of our own Milky Way. This spiral galaxy, named BRI 1335-0417, is more than 12 billion years old and is currently the furthest known of its kind in the entire Universe.
Using the advanced ALMA telescope, lead author Dr. Takafumi Tsukui and his team studied the ancient galaxy in great detail, with particular interest in the movement of gas within and around the galaxy, which is crucial for star formation. By observing the gas dynamics, they captured the formation of a seismic wave, which is a first for this type of early galaxy. The movement of the stars, gas, and dust in the flattened disk of BRI 1335-0417 is similar to ripples forming on a pond after a stone is thrown in.
The latest data has revealed new insights into the formation of our galaxy, which were previously unknown. The ALMA observatory, located in the European Southern Observatory (ESO), boasts an impressive array of 66 antennas that work together to focus on a single galaxy. Each antenna gathers data, which is then merged through a powerful supercomputer to produce a detailed image of the galaxy. This groundbreaking study took place at ALMA, revolutionizing our understanding of the origins of our Universe.
According to Dr. Tsukui, the disk's vertical oscillating motion could be a result of an external force, possibly from new gas entering the galaxy or from coming into contact with smaller galaxies, providing the galaxy with new material for star formation. Additionally, the study revealed a bar-like structure within the disk, which can disrupt gas and transport it towards the center of the galaxy. This distant bar in BRI 1335-0417 is the most distant one known, indicating the dynamic growth of a young galaxy.
Because this galaxy is so far away, its light takes a longer time to reach Earth, allowing us to see images from its early days when the universe was only 10% of its current age. Co-author Associate Professor Emily Wisnioski notes that early galaxies form stars at a much faster rate than modern ones, including BRI 1335-0417, which forms them hundreds of times faster despite having a similar mass to our Milky Way. To understand how gas is supplied to sustain this rapid star formation, they observed rare spiral structures in the early universe. The exact process by which these structures form remains unknown, but this study provides important clues for potential scenarios. While direct observation of a galaxy's evolution is impossible, supercomputer simulations can be used to piece together its story based on snapshots collected through observations like this one.