论文标题
与UC HII区域G45.07+0.13和G45.12+0.13相关的恒星形成区域的红外研究
Infrared study of the star-forming region associated with the UC HII regions G45.07+0.13 and G45.12+0.13
论文作者
论文摘要
UCHII区域是大型恒星形成和早期演变的重要阶段，也是星际介质的关键组成部分。这项工作的主要目的是研究与G45.07+0.13（G45.07）和G45.12+0.13（G45.12）UCHII区域以及它们嵌入其中的星际介质相关的年轻恒星对象（YSO）。我们使用Herschel图像确定了分子云中氢柱密度（N（H2））和尘埃温度（TD）的分布。我们使用红外光度数据来识别和对YSO进行分类。我们还构建了一个颜色 - 磁性图和K光度函数（KLFS），以将YSO的参数与辐射转移模型的结果进行比较。我们发现N（H2）分别在G45.07和G45.12区域内的N（H2）分别从3.0到5.5x10^（23）CM^（-2）。 G45.12中的最大TD值为35K，在G45.07中为42K。 TD分别在IRAS19110+1045（G45.07）和IRAS19111+1048（G45.12）的距离为2.6和3.7％的距离时达到约18-20k。 G45.12中包含的气盘质量值为3.4x10^5msun和1.7 x10^5msun G45.07中的质量值。 UCHII区域通过冷（TD = 19k）桥连接。 518 YSO的密度分布在两个IRAS源周围都表现出密集的簇。 IRAS簇中YSO的参数（124个对象）和394个非集群对象显示出一些差异。属于IRAS群集的YSO中约有75％的进化年龄大于10^6年。他们的KLF的斜率alpha与1myr处的高质量范围（O-f恒星，beta = 2）的Salpeter型初始质量函数（IMF）（伽马= 1.35）非常吻合。非簇对象均匀地分布在分子云中，其中80％位于0.1myr同句的右侧。基于恒星物体的年龄较小，我们建议该簇源于单个触发冲击。
UCHII regions are an important phase in the formation and early evolution of massive stars and a key component of the interstellar medium. The main objectives of this work are to study the young stellar objects (YSOs) associated with the G45.07+0.13 (G45.07) and G45.12+0.13 (G45.12) UCHII regions, as well as the interstellar medium in which they are embedded. We determined the distribution of the hydrogen column density (N(H2)) and dust temperature (Td) in the molecular cloud using Herschel images. We used infrared photometric data to identify and classify the YSOs. We also constructed a colour-magnitude diagram and K luminosity functions (KLFs) to compare the parameters of YSOs with the results of the radiative transfer models. We found that N(H2) varies from about 3.0 to 5.5x10^(23)cm^(-2) within the G45.07 and G45.12 regions, respectively. The maximum Td value is 35K in G45.12 and 42K in G45.07. Td reaches about 18-20K at distances of 2.6 and 3.7pc from IRAS19110+1045 (G45.07) and IRAS19111+1048 (G45.12), respectively. The gas-dust mass value included in G45.12 is 3.4x10^5Msun and 1.7x10^5Msun in G45.07. The UCHII regions are connected through a cold (Td=19K) bridge. The density distribution of 518 YSOs exhibits dense clusters around both IRAS sources. The parameters of YSOs in the IRAS clusters (124 objects) and 394 non-cluster objects surrounding them show some differences. About 75% of the YSOs belonging to the IRAS clusters have an evolutionary age greater than 10^6 years. Their slope alpha of the KLF agrees well with a Salpeter-type Initial Mass Function (IMF) (gamma=1.35) for a high mass range (O-F stars, beta=2) at 1Myr. The non-cluster objects are uniformly distributed in the molecular cloud, 80% of which are located to the right of the 0.1Myr isochrone. Based on the small age spread of the stellar objects, we suggest that the clusters originate from a single triggering shock.
