We aim to investigate the impact of the ionized radiation from the M16 HII region on the surrounding molecular cloud and on its hosted star formation. To present comprehensive multi-wavelength observations towards the M16 HII region, we used new CO data and existing infrared, optical, and submillimeter data. The 12CO J=1-0, 13CO J=1-0, and C18O J=1-0 data were obtained with the Purple Mountain Observatory (PMO) 13.7m radio telescope. To trace massive clumps and extract young stellar objects (YSOs) associated with the M16 HII region, we used the ATLASGAL and GLIMPSE I catalogs, respectively. From CO data, we discern a large-scale filament with three velocity components. Because these three components overlap with each other in both velocity and space, the filament may be made of three layers. The M16 ionized gas interacts with the large-scale filament and has reshaped its structure. In the large-scale filament, we find 51 compact cores from the ATLASGAL catalog, 20 of them being quiescent. The mean excitation temperature of these cores is 22.5 K, while this is 22.2 K for the quiescent cores. This high temperature observed for the quiescent cores suggests that the cores may be heated by M16 and do not experience internal heating from sources in the cores. Through the relationship between the mass and radius of these cores, we obtain that 45% of all the cores are massive enough to potentially form massive stars. Compared with the thermal motion, the turbulence created by the nonthermal motion is responsible for the core formation. For the pillars observed towards M16, the H II region may give rise to the strong turbulence.
Impact of Cosmic-Ray Feedback on Accretion and Chemistry in Circumstellar Disks
我们使用的气体颗粒化学代码UCLCHEM探索宇宙射线反馈的化学拱盘的影响。我们模拟宇宙射线从恒星向外传播时的衰减和能量损失，并考虑恒星辐射和放射性核素引起的电离。对于吸积率典型的年轻恒星，$\dot M_* \sim 10^{-9}-10^{-6}$ M_PDMATHABMN年$^{-1}$，我们表明，宇宙射线加速恒星吸积冲击产生的宇宙射线电离率在磁盘表面$ζ\gtrsim 10^{-15}$ s $^{-1}$，至少一个数量级高于电离率与银河系宇宙射线背景。入射的宇宙射线通量增强了磁盘电离在中间到高表面密度（$Σ> 10$ g cm $^{-2}$），特别是在10 AU的恒星。我们发现，在磁盘表面层的主要离子是C $^+$，S $^+$和Mg $^+$，而H $_3^+$离子占主导地位的表面密度大于1.0 g cm $^{-2}$。我们预测的半径和列密度的磁旋转不稳定性（MRI）是活跃在T金牛座磁盘和宇宙射线反馈的电离扩展的MRI活动区域向磁盘中平面。然而，磁共振成像只有在最小质量太阳星云盘的中平面才是活跃的，如果宇宙射线扩散（$ζ\propto r^{-1}$）远离恒星。加速宇宙射线的吸积、衰减宇宙射线的密集吸积柱和促进吸积的MRI之间的关系，创建了一个介导吸积的宇宙射线反馈回路，并可能产生光度变化。
Quantifying the Influence of Key Physical Processes on the Formation of Emission Lines Observed by IRIS: I. Non-Equilibrium Ionization and Density-Dependent Rates
Observations of Protostellar Outflow Feedback in Clustered Star Formation
我们讨论了原恒星外流反馈的作用，在集群恒星形成的观测数据，最近的分子外流调查对附近的集群形成团块。我们发现，对于几乎所有的团块，流出动量注入率是显着大于湍流耗散率。因此，外流反馈很可能维持团簇中的超音速湍流。对于质量较小的团块，如B59、L1551和L1641 N，流出的动能与团块的引力能相当。在这样的集群，外流反馈可能会影响显着的集群动力学。另一方面，对于质量大于约200 M $_\odot$的团块，流出动能明显小于团块的重力能。由于大多数恒星都是在这样的团块中形成的，我们得出结论，外流反馈不能摧毁整个母体团块。外流反馈的这些特征支持恒星形成缓慢的假设。
Ionisation-induced star formation III: Effects of external triggering on the IMF in clusters
我们报告的光滑粒子流体动力学（SPH）模拟的影响湍流$\sim2\times10^{3}$ M $_{\odot}$星-形成分子云的辐射由外部源的电离光子。我们发现电离辐射对气体形态有显著的影响，但对触发恒星的作用不太重要。恒星形成的速率和形态在很大程度上取决于湍流速度场产生的气体结构，反馈对恒星初始质量函数没有明显的影响。虽然许多年轻的恒星是在位于电离前沿附近的致密气体中发现的，但大多数这些物体也是在没有反馈的情况下形成的。电离在云的扩散区域有更强的作用，它会把低密度的气体扫走，否则这些气体就不会形成恒星，成为引力不稳定的团块。然而，即使在这些区域，恒星之间的动力学相互作用也会迅速消除它们的位置和速度与电离前沿之间的相关性。
