We present near-IR SINFONI observations of three Galactic HII regions: RVW79, RCW82 and RCW120. We identify the ionizing stars of each region: they are early to late O stars, close to the main sequence. We derive their stellar and wind properties using atmosphere models computed with the code CMFGEN. The cluster ionizing RCW~79 formed 2.3+/-0.5 Myr ago. Similar ages are estimated, albeit with a larger uncertainty, for the ionizing stars of the other two regions. In RCW79 the mechanical wind luminosity represents only 0.1% of the ionizing luminosity, questioning the influence of stellar winds on the dynamics of the the HII region. The young stellar objects show four main types of spectral features: H2 emission, Br gamma emission, CO bandheads emission and CO bandheads absorption. These features are typical of young stellar objects surrounded by disks and/or envelopes. The radial velocities of most YSOs are consistent with that of the ionized gas, firmly establishing that star formation is taking place on the borders of the HII regions. Outflows are detected in a few YSOs. All YSOs have moderate to strong near-IR excess. In the [24] versus K-[24] diagram, the majority of the sources dominated by H2 emission lines stand out as redder and brighter than the rest of the YSOs. Their H2 emission is mainly due to shocks. We tentatively propose that they represent an earlier phase of evolution compared to sources dominated by Br gamma and CO bandheads. We suggest that they still possess a dense envelope in which jets or winds create shocks. The other YSOs have partly lost their envelopes and show signatures of accretion disks.
Impact of initial models and variable accretion rates on the pre-main-sequence evolution of massive and intermediate-mass stars and the early evolution of HII regions
Three-dimensional modeling of ionized gas. II. Spectral energy distributions of massive and very massive stars in stationary and time-dependent modeling of the ionization of metals in HII regions
Detailed Numerical Simulations on the Formation of Pillars around HII-regions
我们研究了湍流分子云的结构演化的影响下，从附近的大质量恒星发出的电离辐射进行高分辨率参数研究与IVINE代码。温度取10 K或100 K，平均数密度取100 cm ^3或300 cm ^3。此外，湍流度在马赫数1.5 ~ 12.5之间变化，主要驱动尺度在1 pc ~ 8 pc之间。我们改变电离通量一个数量级。在我们的模拟中，电离辐射增强了初始湍流密度分布，从而导致在HII区域附近以自然方式观察到的柱状结构的形成。引力坍缩在结构的顶端有规律地发生。我们发现一个明确的相关性之间的初始状态的湍流冷云和最终的形态和物理性质的结构形成。形成柱状物的最有利条件是马赫数4-10。只有当高密度非离子化气体和将要被离子化的气体之间的初始密度差低于热气体和冷气体之间的温度差时，结构和恒星才会形成。所得柱的密度由热气体和冷气体之间的压力平衡确定。对模拟结果的全面分析表明，所形成的细长细丝的复杂运动学和几何结构反映了所观察到的柱子的细节，其细节程度令人印象深刻。此外，我们发现，所观察到的视线速度允许不同的形成机制的一个不同的确定。将当前的模拟与以前的结果和最近的观测进行比较，我们得出结论，例如，M16中的创造之柱是由这里提出的机制形成的，而不是由辐射驱动的预先存在的团块的内爆形成的。
Numerical Models for the Diffuse Ionized Gas in Galaxies. II. Three-dimensional radiative transfer in inhomogeneous interstellar structures as a tool for analyzing the diffuse ionized gas
MHD Simulations of Strongly Magnetized HII Region Evolution: Evidence for Ionized Gas Filamentation
Oxford Centre for the History of Science, Medicine, and Technology, University of Oxford（牛津大学科学、医学与技术历史中心）；Dept. of Astronomy, University of Virginia（弗吉尼亚大学天文学系）；Virginia Institute of Theoretical Astronomy, University of Virginia（弗吉尼亚大学理论天文研究所）；Department of Astronomy, University of Michigan（密歇根大学天文学系）；Korea Institute of Advanced Study（韩国高等研究院）；Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences University of Colorado, Boulder（科罗拉多大学博尔德分校天体物理与行星科学系天体物理学与太空天文中心）
