The center of the Milky Way is the most prolific star-forming region in the entire Galaxy.
However, astronomers have only found a fraction of the young stars they expected here: there is “fossil” evidence that many more stars were born in the recent past than we actually see.
That’s because looking toward the center of the Milky Way is no easy feat: clouds of dust and gas block starlight and obscure the view.
“The galactic center stands out as the most prolific star-forming environment in the galaxy when its volume is averaged,” said Dr. Francisco Nogueras Lara, ESO astronomer.
“In the last 30 million years it has witnessed the formation of around a million stars.”
“However, crowding and high extinction make their detection difficult, and so far only a small fraction of the expected mass of young stars has been identified.”
Dr. Lara aimed to detect young stars hidden in the galactic center by studying the stellar population in Sagittarius C.
In the study, he analyzed data from the HAWK-I Infrared Instrument on ESO’s Very Large Telescope.
He found that Sagittarius C was much richer in young stars than other areas of the galactic center.
“We found that Sagittarius C hosts several hundred thousand solar masses of young stars,” Dr. Lara said.
“We compare our results with the recently discovered young stellar population in Archer B1which is located on the opposite edge of the nuclear stellar disk.”
“We estimate that the young stars of Sagittarius C are around 20 million years old and probably show the next evolutionary step of the slightly younger stars of Sagittarius B1.”
“Our findings help address the discrepancy between the expected and detected numbers of young stars in the galactic center, and shed light on their evolution in this extreme environment.”
“As a secondary result, we found an intermediate-age stellar population in Sagittarius C (about 50% of its stellar mass with an age between 2 and 7 billion years), which is not present in the innermost regions of the stellar disk. nuclear. (dominated by stars over 7 billion years old).”
“This supports the existence of an age gradient and favors an inside-out formation of the nuclear stellar disk.”
He recommendations appear in the magazine Astronomy and Astrophysics.
F. Nueces-Lara et al. 2024. Hunting young stars in the galactic center. Hundreds of thousands of solar masses of young stars in the C region of Sagittarius. AA 681, L21; two: 10.1051/0004-6361/202348712