论文标题
在银河中心射手座B1地区检测过多的年轻恒星
Detection of an excess of young stars in the Galactic center Sagittarius B1 region
论文作者
论文摘要
银河系的中心是最接近的星系核，也是银河系中最极端的环境。尽管它的体积不到银河磁盘的1％，但在过去的100个MYR中，银河系中所有新生恒星中最多可达10％。因此，它构成了在极端条件下了解恒星形成的理想实验室，类似于Starburst或High-Redshift星系中的恒星形成。但是，仅有的两个已知的银河中心年轻簇占预期恒星质量的10％。我们分析了射手座（SGR）B1的星形形成历史，这是一个与强大的HII排放相关的银河中心区域，并找到了有几个$ 10^5 $太阳能的年轻恒星的证据，形成了$ \ sim $ 10 $ 10 MYR。我们还检测到SGR B1中中间年龄恒星（2-7 Gyr）的存在，在核恒星磁盘的内部区域似乎很少见（或不存在），并且可能表明内而外的形成。我们的结果构成了朝着更好地理解银河系中心的恒星形成的大步，例如年轻群集的命运以及该区域中可能不同的初始质量功能。
The Milky Way's center is the closest galaxy nucleus and the most extreme environment of the Galaxy. Although its volume is less than 1% of that of the Galactic disk, up to 10% of all new-born stars in the Galaxy in the past 100 Myr formed there. Therefore, it constitutes a perfect laboratory to understand star formation under extreme conditions, similar to those in starburst or high-redshift galaxies. However, the only two known Galactic center young clusters account for <10% of the expected young stellar mass. We analyze the star formation history of Sagittarius (Sgr) B1, a Galactic center region associated with strong HII emission, and find evidence for the presence of several $10^5$ solar masses of young stars, that formed $\sim$10 Myr ago. We also detect the presence of intermediate age stars (2-7 Gyr) in Sgr B1 that appear to be rare (or absent) in the inner regions of the nuclear stellar disk, and might indicate inside out formation. Our results constitute a large step toward a better understanding of star formation at the Galactic center, such as the fate of young clusters, and the possibly different initial mass function in this region.
