A spatially-resolved study of initial mass function in the outer Galaxy
A spatially-resolved study of initial mass function in the outer Galaxy
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外星系初始质量函数的空间分辨研究
DOI：
10.1017/s174392131600942x
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Naoto
中科院分区：
文献类型：
--
作者：
Yasui;Chikako; Izumi;Natsuko; Saito;Masao; Kobayashi;Naoto
螺旋星系的外围，包括我们自己的，和矮不规则星系已知有一个不同的环境从太阳附近，例如，低金属丰度（~− 1 dex）。其中，外星系是最近的，因此是迄今为止唯一的网站适合于人口研究的解决恒星在同一基础上的太阳邻域。我们已经获得了近红外图像的年轻的星系外，使用斯巴鲁8.2米望远镜，并清楚地解决了集群成员的质量检测限为~0.1 M <$。通过对4个星系团K波段光度函数（KLF）的拟合，发现银河系外星系团的初始质量函数（IMF）与太阳附近星系团的初始质量函数在高质量斜率和IMF峰值方面是一致的。即将进行的观测具有更高的空间分辨率和灵敏度，使用JWST、TMT等，将使我们能够扩展IMF的空间分辨研究到本星系群。
Outskirts of spiral galaxies, including our own, and dwarf irregular galaxies are known to have a different environment from the solar neighborhood, e.g., low metallicities ( ~ − 1 dex). Among them, the outer Galaxy is the closest and hence is so far the only site suitable for population studies of resolved stars on the same basis as solar neighborhood. We have obtained NIR images of young clusters in the outer Galaxy, using the Subaru 8.2-m telescope, and clearly resolved cluster members with mass detection limits of ~ 0.1 M⊙. Based on the fitting of K-band luminosity functions (KLFs) for four clusters, we found that the initial mass function (IMF) in the outer Galaxy is consistent with that in the solar neighborhood in terms of the high-mass slope and IMF peak. Upcoming observations with a higher spatial resolution and sensitivity, using JWST, TMT, etc., will allow us to extend spatially-resolved studies of the IMF to Local Group galaxies.