Sagittarius C is located just 300 light-years from Sagittarius A*, the supermassive black hole at the center of the Milky Way.
The center of the Milky Way is the most prolific star-forming region in the entire galaxy.
But astronomers have discovered only a fraction of the young stars they had expected. There is “fossil” evidence that many more stars than we actually see were born recently.
This is because heading to the center of the Milky Way is not an easy task. Clouds of dust and gas block the light from the star, obscuring visibility.
“On average by volume, the galactic center stands out as the most prolific star-forming environment in the galaxy,” said ESO astronomer Francisco Nogueras Lara.
“Over the past 30 million years, we have witnessed the formation of about 1 million stars.”
“But crowding and high extinction rates have hampered their discovery, and so far only a fraction of the young star's expected mass has been confirmed.”
By studying the stellar population of Sagittarius C, Dr. Lara aimed to detect young stars hidden in the galactic center.
In his research, he analyzed the following data: HAWK-I infrared measuring instrument ESO's Very Large Telescope.
He found that Sagittarius C is much richer in young stars than other regions of the galactic center.
“We found that Sagittarius C contains the solar mass of hundreds of thousands of young stars,” Dr. Lara said.
“We compared our results to a recently discovered population of young stars in Sagittarius B1, located at the opposite end of the nuclear star disk.”
“The young stars in Sagittarius C are estimated to be about 20 million years old and likely represent the next evolutionary step for the slightly younger stars in Sagittarius B1.”
“Our discovery contributes to addressing the discrepancy between the expected number of young stars at the center of galaxies and the number of detected stars, and sheds light on their evolution in this extreme environment.”
“As a secondary result, we discovered that Sagittarius C has a population of intermediate-aged stars (approximately 50% of the mass of stars between 2 billion and 7 billion years old), which is composed of a nuclear stellar disk. It does not exist in the innermost region of the world (which is dominated by stars older than 7 billion years).
“This confirms the existence of an age gradient, driving the formation of an inside-out nuclear star disk.”
of findings appear in the diary astronomy and astrophysics.
F. Nogueras-Lara other. 2024. Hunt young stars at the center of the galaxy. Solar masses of hundreds of thousands of young stars in the Sagittarius C region. A&A 681, L21; doi: 10.1051/0004-6361/202348712