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首页> 外文期刊>The Astrophysical journal >DUSTY CRADLES IN A TURBULENT NURSERY: THE SGR A EAST H II REGION COMPLEX AT THE GALACTIC CENTER
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DUSTY CRADLES IN A TURBULENT NURSERY: THE SGR A EAST H II REGION COMPLEX AT THE GALACTIC CENTER

机译:湍流苗圃中的尘土飞扬:银河中心地区的东部H II地区复合体

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摘要

We present imaging at 19, 25, 31, and 37 μm of the compact H II region complex G-0.02-0.07 located 6 pc in projection from the center of the Galaxy obtained with SOFIA using FORCAST. G-0.02-0.07 contains three compact H II regions (A, B, and C) and one ultra-compact H II region (D). Our observations reveal the presence of two faint, infrared sources located 23'' and 35'' to the east of region C (FIRS 1 and 2) and detect dust emission in two of the three "ridges" of ionized gas west of region A. The 19/37 color temperature and 37 μm optical depth maps of regions A-C are used to characterize the dust energetics and morphology. Regions A and B exhibit average 19/37 color temperatures of ~105 K, and regions C and D exhibit color temperatures of ~115 K and ~130 K, respectively. Using the DustEM code, we model the SEDs of regions A-D and FIRS 1, all of which require populations of very small, transiently heated grains and large, equilibrium-heated grains. We also require the presence of polycyclic aromatic hydrocarbons in regions A-C in order to fit the 3.6, 4.5, 5.8, and 8.0 μm fluxes observed by Spitzer/IRAC. The location of the heating source for region A is determined by triangulation from distances and temperatures derived from DustEM models fit to SEDs of three different points around the region, and it is found to be displaced to the northeast of the center of curvature near the color temperature peak. Based on total luminosity, expected 1.90 μm fluxes, and proximity to the mid-IR color temperature peaks, we identify heating source candidates for regions A, B, and C. However, for region D, the observed fluxes at 1.87 and 1.90 μm of the previously proposed ionizing star are a factor of ~40?times too bright to be the heating source and hence is likely just a star lying along the line of sight toward region D.
机译:我们介绍了在19、25、31和37μm的紧凑型H II区域复合物G-0.02-0.07处成像,该投影距使用SOFIA使用FORCAST获得的银河中心投影距离6 pc。 G-0.02-0.07包含三个紧凑的H II区域(A,B和C)和一个超紧凑的H II区域(D)。我们的观察结果表明,在C区以东23英寸和35英寸处(FIRS 1和2)存在两个微弱的红外源,并检测到A区以西三个电离气体“脊”中的两个“粉尘”中的粉尘排放。使用AC区域的19/37色温和37μm的光学深度图来表征粉尘的能量和形态。 A和B区的平均19/37色温为〜105 K,C和D区的平均色温分别为〜115 K和〜130K。使用DustEM代码,我们对A-D和FIRS 1区域的SED进行建模,所有这些都需要非常小的,短暂加热的晶粒和大的,平衡加热的晶粒的种群。我们还要求在A-C区域中存在多环芳烃,以适应Spitzer / IRAC观察到的3.6、4.5、5.8和8.0μm通量。区域A的加热源位置是通过三角测量确定的,该距离是根据DustEM模型得出的距离和温度进行拟合确定的,该距离和温度与该区域周围三个不同点的SED拟合,并且发现该位移移至颜色附近曲率中心的东北温度峰值。根据总亮度,预期的1.90μm通量以及接近中红外色温峰,我们确定区域A,B和C的候选热源。但是,对于区域D,在1.87和1.90μm处观察到的通量先前提出的电离星的亮度约为40倍,无法作为加热源,因此很可能只是沿着视线朝着D区的一颗恒星。

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