论文标题
研究Messier 8 East中巨大恒星形成的效果和原因
Studying the effects and cause of the massive star formation in Messier 8 East
论文作者
论文摘要
Messier 8（M8）是我们银河系中最亮的HII地区之一，与两个突出的巨大恒星形成区域相关：M8-Main，大规模HII地区特别明亮的部分（主要是由Stellar System Hershel 36（她的36）和M8 East（M8 E）发出的，这是一个由深度启动的Irs in Ir in Ir and in Ir nimperder nimperder nound in Ir y s的ir（ir），这是一个年轻的（IR），这是一个年轻的（IR），这是一个年轻的（IR）（IR）。资料来源，m8e-ir。我们的目的是研究大规模恒星区域M8 E与周围环境的相互作用，并比较M8-Main和M8 E的星形成环境。我们使用IRAM 30 M望远镜对M8E-IR的分子环境进行成像光谱调查。我们对$ j $ = 1 $ \至$ 0的数据进行了成像和分析，$^{12} $ co，$^{13} $ co，n $ _2 $ _2 $ _2 $ _2 $ h $^+$，hcn，h $^{13} $ cn，hco $^+$，h $，h $，h $，h $，h $^{13} $ $^$^$^$^$^+^$^$^+^$^+^$^$^+^+^+^$^$^+^$朝向m8〜e。我们使用LTE和非LTE技术来确定观察到的物种的色谱柱密度，并限制对其发射负责的气体的物理条件。检查M8〜E中的YSO群体使我们能够探索观察到的电离前线（如果），如瞥见8〜 $μ$ M发射图像所示。我们发现$^{12} $ co探测了瞥见8〜 $μ$ m排放的温暖散射气体，而n $ _2 $ _2 $ h $^+$和hn $^{13} $ c追踪凉爽且浓密的气体。我们发现，M8〜E中的恒星形成似乎是由较早形成的恒星群集NGC〜6530触发的，该恒星群集NGC〜6530为HII区域提供动力，从而引起了IF的速度$ \ geQ $ 0.26〜 km〜S $^s $^{ - 1} $。我们分别为温暖和凉爽的气体组件得出80 K和30 K的温度，并限制了h $ _2 $的体积密度在10 $^4 $ -10 $ -10 $^6 $^6 $ 〜cm $^{ - 3} $。观察到的各种物种的丰富性的比较反映了以下事实：M8〜E比M8-Main的恒星形成更早的阶段。
Messier 8 (M8), one of the brightest HII regions in our Galaxy, is associated with two prominent massive star-forming regions: M8-Main, the particularly bright part of the large scale HII region (mainly) ionised by the stellar system Herschel 36 (Her 36) and M8 East (M8 E), which is mainly powered by a deeply embedded young stellar object (YSO), a bright infrared (IR) source, M8E-IR. We aim to study the interaction of the massive star-forming region M8 E with its surroundings and to compare the star-forming environments of M8-Main and M8 E. We used the IRAM 30 m telescope to perform an imaging spectroscopy survey of the molecular environment of M8E-IR. We imaged and analysed data for the $J$ = 1 $\to$ 0 rotational transitions of $^{12}$CO, $^{13}$CO, N$_2$H$^+$, HCN, H$^{13}$CN, HCO$^+$, H$^{13}$CO$^+$, HNC and HN$^{13}$C observed for the first time toward M8~E. We used LTE and non-LTE techniques to determine column densities of the observed species and to constrain the physical conditions of the gas responsible for their emission. Examining the YSO population in M8~E allows us to explore the observed ionization front (IF) as seen in GLIMPSE 8~$μ$m emission image. We find that $^{12}$CO probes the warm diffuse gas also traced by the GLIMPSE 8~$μ$m emission, while N$_2$H$^+$ and HN$^{13}$C trace the cool and dense gas. We find that the star-formation in M8~E appears to be triggered by the earlier formed stellar cluster NGC~6530, which powers an HII region giving rise to an IF that is moving at a speed $\geq$ 0.26~km~s$^{-1}$ across M8~E. We derive temperatures of 80 K and 30 K for the warm and cool gas components, respectively, and constrain H$_2$ volume densities to be in the range of 10$^4$--10$^6$~cm$^{-3}$. Comparison of the observed abundances of various species reflects the fact that M8~E is at an earlier stage of massive star formation than M8-Main.
