Sagittarius B1, a region close to the center of our Milky Way Galaxy, hosts more than 100,000 solar masses of young stars.
“The Milky Way’s center is the closest galaxy nucleus and the most extreme environment in the our Galaxy,” said Dr. Francisco Nogueras-Lara from the Max-Planck Institute for Astronomy and colleagues.
“Although its volume is less than 1% of that of the Galactic disk, up to 10% of all new stars in the Galaxy in the past 100 million years formed there.”
“It therefore constitutes a perfect laboratory to understand star formation under extreme conditions, similar to those in star-forming or extremely distant galaxies.”
In new research, Dr. Nogueras-Lara and his co-authors from Germany and Spain analyzed the star formation history of the Sagittarius (Sgr) B1 region.
“Sgr B1 is a well-known region associated with strong HII emission in the nuclear stellar disk,” they explained.
“Far-infrared observations suggest the presence of widely spaced hot stars that excite the gas in at least eight separate subregions.”
“Moreover, a cohort of six young massive stars have been detected there.”
Using the High Acuity Wide field K-band Imager (HAWK-I) infrared instrument on ESO’s Very Large Telescope, the researchers studies a field of 160 sq. parsecs covering part of Sgr B1.
They found evidence for the presence of several tens of thousands of solar masses of stars that formed 10 million years ago.
“Our results contribute to a more general picture of the evolution of the young stars in the Galactic center in which stars form in massive stellar associations that can contain clusters — Sagittarius B2 is an example of this stage — and later disperse while orbiting through the nuclear stellar disk,” they said.
“Our findings also help us to understand the isolated massive stars detected across the Galactic center, whose proper motions indicate that they are not related to the known young clusters, supporting their formation in stellar associations or gravitationally bound clusters that dispersed on relatively short timescales after their formation several million years ago.”
The team’s paper was published this month in the journal Nature Astronomy.
F. Nogueras-Lara et al. Detection of an excess of young stars in the Galactic Centre Sagittarius B1 region. Nat Astron, published online August 25, 2022; doi: 10.1038/s41550-022-01755-3
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