Topic: Astronomers detected a Giant Stellar Stream around Sombrero Galaxy
Source: Sci News
The Sombrero galaxy is likely to have merged with the relatively massive Milky Way several billion years ago. In a new study published in Monthly Notices of the Royal Astronomical Society, astronomers aimed to detect any tidal structures — such as stellar currents and tails — with wide-field deep images of the outskirts of the Sombrero galaxy obtained with a small amateur telescope. Analyzed possible ancient mergers.
The Sombrero galaxy is located approximately 28 million light-years away in the constellation of Virgo.
Also known as Messier 104, M104 or NGC 4594, the galaxy was discovered by French astronomer Pierre Méchen on May 11, 1781.
Its diameter is about 49,000 light-years, which is about 3 times smaller than our Milky Way galaxy.
“The Sombrero galaxy shows characteristics of the major types of galaxies in the universe, both spiral and elliptical,” said Dr. David Martínez-Delgado, an astronomer at the Instituto de Astrofísica de Andalucía – CSIC and his colleagues.
“It has spiral arms, and a very large bright central bulge, which makes it look like a hybrid of two types.”
The recent discovery of extremely metal-rich stars in the halo of the Sombrero galaxy suggested that the galaxy had recently undergone a major merger with the relatively massive Milky Way.
“According to the latest cosmological model, large spiral galaxies like the Milky Way evolved by absorbing smaller galaxies, a type of galactic cannibalism,” the astronomers said.
“Evidence for this is given by the very large structures, tidal stellar currents observed around them, which are the remains of these satellite galaxies.”
“But the full history of most of these cases is difficult to study, because these star flows are very slow, and only the remnants of the most recent merger have been detected.”
In the new study, researchers observed a ring-like tidal structure in the inner halo region of the Sombrero galaxy.
“It is remarkable that thanks to these advanced photometric techniques, we are able to do front-line science with Messier objects using only an 18-cm-diameter telescope,” said co-author Dr. Javier Roman, postdoctoral researcher at the Instituto de Astrofísica de Andalusia – CSIC, Instituto de Astrophísica de Canarias, and the Universidad de la Laguna.
The team’s result is consistent with the hypothesis that the Milky Way was formed 3.5 billion years ago by a ‘weight major merger’ event that warmed the stellar population.
“A ‘wet merger’ is a scenario in which a large elliptical galaxy is rejuvenated by large amounts of gas and dust from another massive galaxy, which went into the formation of the disk we now see,” he said. Said.
“In our discovery, we have been able to trace for the first time the entire tidal stream that surrounds the disk of the Sombrero galaxy and our theoretical simulations have let us reconstruct its formation over the past 3 billion years by satellite dwarf cannibalism. “
Astronomy News- Astronomers detected a Giant Stellar Stream around Sombrero Galaxy The Sombrero galaxy is likely to have merged with the relatively