Astronomers from the Astrophysical Center of the Australian Research Council (ASTRO) have discovered a spiral galaxy in the constellation Ophiuchus, which has properties similar to the Milky Way.
Previously, scientists believed that the Milky Way did not experience starbursts, but the opposite was recently proved: scientists have found several populations of stars, presumably generated during its collisions with other galaxies, which occurred about 5.7, as well as 1.9 and 1 billion years ago.
The disk of our galaxy consists of two parts: a thin disk and a thick disk. The second arose about 8.6 billion years ago as a result of the fact that the Milky Way collided or merged with another fairly large galaxy.
This event led to the fact that a significant portion of the ancient stars were ejected from the disk of the galaxy, forming a rarefied layer about a thousand light-years thick surrounding the thin disk.
Traditionally, it is believed that the thick and thin discs of the Milky Way arose in the distant past as a result of a particularly strong collision between our galaxy and one of its neighbors. For this reason, astronomers believed that something similar should not be found among other spiral galaxies. Our observations indicate that these theories are most likely wrong.
Nicholas Scott, Research Fellow at ASTRO
After that, the authors of the work studied the galaxy UGC 10738, which is located in the constellation Ophiuchus at a distance of 320 million light years from the Milky Way. Taking pictures of it using the VLT telescope installed at the Chilean Paranal Observatory, scientists found that its disk also consists of two separate parts.
However, scientists have not found any evidence that this galaxy in the past collided with other objects. This, they say, means that this kind of structure can appear on its own.