论文标题
金属贫穷的星系NGC 6822中的尘土飞扬的出生和死亡
Dusty Stellar Birth and Death in the Metal-Poor Galaxy NGC 6822
论文作者
论文摘要
附近的（$ \ sim $ 500 kpc）金属罚款（[fe/h] $ \ $ \ $ -1.2; $ z $ \ $ 30％$ 30％$ z _ {\ odot} $）星形的Galaxy NGC 6822具有类似于高峰星级组合系统的金属性。因此，通过识别和研究尘土飞扬和灰尘的恒星，它是一个有用的实验室，可以阐明早期宇宙中的尘埃生命周期。我们提供了一系列的目录，结合了英国红外望远镜（Ukirt; $ j $，$ h $和$ k $）的近红外和中期光度，以及$ spitzer $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ MIPS 24 $ MIPS 24 $ MIPS 24 $ MIPS $ MIPS $ MIPS）。该目录被用来鉴定NGC 6822中的尘土和进化的恒星，利用三个颜色磁性图（CMD）。鉴于跨IR的诊断CMD涵盖波长范围，我们使用内核密度估算（KDE）技术开发颜色切割，以鉴定产生粉尘的恒星，包括红色超级恒星（RSG）和热 - 垂垂刺激的渐变型巨型巨型分支（TP-AGAGB）恒星候选人。我们总共报告了1,292名RSG候选者，1,050个氧气富含AGB的候选者和560个富含碳的AGB星星，对NGC 6822具有很高的信心。我们对AGB星星的分析表明，我们对Galaxy的中央恒星属于Galaxy的中央恒星杆，其中有一个有衡量的Globallar pmerity $ $ pmerity $ $ $ $ $ 2. 0.095，与以前的研究一致。此外，我们确定了277个年轻恒星对象（YSO）候选人。在集中，紧凑的集群中检测大量YSO候选物，揭示了存在一个嵌入的高质量恒星形成区域，该区域已避免了先前的详细研究。 Spitzer我似乎比银河系中其他著名的恒星形成区域更年轻，更活跃。
The nearby ($\sim$500 kpc) metal-poor ([Fe/H] $\approx$ -1.2; $Z$ $\approx$ 30% $Z_{\odot}$) star-forming galaxy NGC 6822 has a metallicity similar to systems at the epoch of peak star formation. Through identification and study of dusty and dust-producing stars, it is therefore a useful laboratory to shed light on the dust life cycle in the early Universe. We present a catalog of sources combining near- and mid-IR photometry from the United Kingdom Infrared Telescope (UKIRT; $J$, $H$, and $K$) and the $Spitzer$ $Space$ $Telescope$ (IRAC 3.6, 4.5, 5.8, and 8.0 $μ$m and MIPS 24 $μ$m). This catalog is employed to identify dusty and evolved stars in NGC 6822 utilizing three color-magnitude diagrams (CMDs). With diagnostic CMDs covering a wavelength range spanning the near- and mid-IR, we develop color cuts using kernel density estimate (KDE) techniques to identify dust-producing evolved stars, including red supergiant (RSG) and thermally-pulsing asymptotic giant branch (TP-AGB) star candidates. In total, we report 1,292 RSG candidates, 1,050 oxygen-rich AGB star candidates, and 560 carbon-rich AGB star candidates with high confidence in NGC 6822. Our analysis of the AGB stars suggests a robust population inhabiting the central stellar bar of the galaxy, with a measured global stellar metallicity of [Fe/H] = -1.286 $\pm$ 0.095, consistent with previous studies. In addition, we identify 277 young stellar object (YSO) candidates. The detection of a large number of YSO candidates within a centrally-located, compact cluster reveals the existence of an embedded, high-mass star-formation region that has eluded previous detailed study. Spitzer I appears to be younger and more active than the other prominent star-forming regions in the galaxy.
