论文标题
巨大恒星群集Westerlund的距离和年龄1。使用GAIA-EDR3的视差方法
Distance and age of the massive stellar cluster Westerlund 1. I. Parallax method using Gaia-EDR3
论文作者
论文摘要
Westerlund 1（WD 1）是银河系中最庞大的年轻明星集群之一。尽管与恒星形成和进化有关，但其基本参数尚未受到很好的约束。我们旨在得出准确的距离，并为群集年龄提供约束。我们使用了Gaia早期数据版本3（GAIA-EDR3）中可用的光度法和星体信息来推断其4.06 $^{+0.36} _ { - 0.34} $ KPC的距离。在论文II中报道的黯然失色的二进制系统W36的建模导致4.03 $ \ pm $ 0.25 kpc的距离与GAIA-EDR3距离一致，因此验证了适合红对象的视差零点校正方法。基于这两种方法的加权平均距离导致D $ _ {\ rm WD1} $ = 4.05 $ \ pm $ 0.20 kpc（$ m-m $ = 13.04 $^{+0.11} _ { - 0.12} $），其准确性为5％。使用太阳丰度的红色超级巨人的二元种群和光谱合成模型，我们得出了10.7 $ \ pm $ 1 MYR的年龄，与Beasor＆Davies最近的工作非常吻合（10.4 $^{+1.3} _ {-1.2} _ { - 1.2} $ R），基于雾化的进化模型。据报道，在论文II中，W36B的年龄为6.4 $ \ pm $ 0.5 MYR，这支持了最近关于WD 1中几种MYRS的暂时性差异的主张，而不是单个单片的Starburst情节。
Westerlund 1 (Wd 1) is one of the most massive young star clusters in the Milky Way. Although relevant for star formation and evolution, its fundamental parameters are not yet very well constrained. We aim to derive an accurate distance and provide constraints on the cluster age. We used the photometric and astrometric information available in the Gaia Early Data Release 3 (Gaia-EDR3) to infer its distance of 4.06$^{+0.36}_{-0.34}$ kpc. Modelling of the eclipsing binary system W36, reported in Paper II, led to the distance of 4.03$\pm$0.25 kpc, in agreement with the Gaia-EDR3 distance and, therefore, validating the parallax zero-point correction approach appropriate for red objects. The weighted average distance based on these two methods results in d$_{\rm wd1}$=4.05$\pm$0.20 kpc ($m-M$=13.04$^{+0.11}_{-0.12}$ mag), which has an unprecedented accuracy of 5%. Using the Binary Population and Spectral Synthesis (BPASS) models for the Red Supergiants with solar abundance, we derived an age of 10.7$\pm$1 Myr, in excellent agreement with recent work by Beasor & Davies (10.4$^{+1.3}_{-1.2}$ Myr) based on MIST evolutionary models. In Paper II, the age of W36B was reported to be 6.4$\pm$0.5 Myr, supporting recent claims of a temporal spread of several Myrs for the star-forming process within Wd 1 instead of a single monolithic starburst episode scenario.
