Studies of Star Formation with Galactic Plane Surveys

该计划通过利用最近的银河系平面调查的丰富协同作用来研究恒星形成过程，该调查追踪了星际气体和尘埃的不同阶段和条件。主要重点是综合这些集体调查数据集中的信息，为银河系内盘恒星形成的物理学提供最完整的观测约束。特别是，在一个巨大的分子云内部的物理过程，负责大质量团块的发展，从星团和OB星凝聚被研究。这些数据集包括FCRAO（五校射电天文台）12CO和13CO发射巡天、Bolocam星系面巡天（BGPS）、甚大阵列（VLA）星系面巡天和斯皮策遗产项目斯皮策内星系面巡天多波段成像光度计（MIPSGAL）。通过将毫米波、尘埃和无线电连续体测量中确定的来源与13CO发射速度联系起来，人们可以在银河系不同环境和位置的巨大分子云中获得恒星形成活动的测量结果。这类测量包括存在于大质量团块内的云团质量的比例，由红外光度得出的恒星形成率，以及由射电光度得出的莱曼- α连续体光子的普查。这些性质与13CO发射的母分子云的动力学状态和速度结构进行了比较。这些集体信息被用来评估由星际湍流和不断扩大的电离锋驱动的激波在调节恒星形成方面的作用。该项目的一部分工作是校准一组云的尺寸-速度色散关系系数，这些云的距离已通过三角视差测量确定为优于10%。这一校准为银河系中巨大的分子云建立了一种新的距离测量方法，可以补充或改进由银河系旋转曲线得出的运动距离。在银河系中建立一个新的距离测量对研究银河系结构和单个恒星形成区域具有重要意义。在项目期间，网站上提供了恒星形成区域的汇编。这些数据集的多波长、多维特征要求开发和使用可应用于其他天文数据的广义多变量方法。这个项目是博士论文的基础；它将使受资助的研究生充分参与，从而有助于培养下一代科学家。

This program investigates the star formation process by exploiting the rich synergy of recent Galactic Plane Surveys that trace various phases and conditions of interstellar gas and dust. The main focus is to synthesize the information resident within these collective survey data sets to provide the most complete observational constraints to the physics of star formation in the inner disk of the Galaxy. In particular, physical processes within a giant molecular cloud responsible for the development of massive clumps from which clusters and OB stars condense are investigated.The data sets include the FCRAO (Five College Radio Astronomy Observatory) surveys of 12CO and 13CO emission, the Bolocam Galactic Plane Survey (BGPS), the Very Large Array (VLA) Galactic Plane Survey, and the Spitzer Legacy program Multiband Imaging Photometer for Spitzer Inner Galactic Plane Survey (MIPSGAL). By linking sources identified within the millimeter, dust, and radio continuum surveys to velocities of 13CO emission, one obtains measures of the star formation activity within giant molecular clouds over varying environments and locations in the Galaxy. Such measures include the fraction of cloud mass residing within massive clumps, star formation rates derived from infrared luminosity, and a census of Lyman-alpha continuum photons from the radio luminosity. These properties are compared to the dynamical state and velocity structure of the parent molecular cloud derived from 13CO emission. This collective information is used to evaluate the role of shocks driven by interstellar turbulence and expanding ionization fronts on regulating star formation.Part of this project is to calibrate the coefficient of the size-velocity dispersion relationship for a set of clouds whose distances have been determined to better than 10% by trigonometric parallax measurements. This calibration then establishes a new distance measure for giant molecular clouds in the Milky Way that can complement or improve upon kinematic distances derived from the Galactic rotation curve.The establishment of a new distance measure in the Galaxy significantly aids studies of Galactic structure and investigations of individual star forming regions. A compilation of star forming regions is made available on the web during the project. The multi-wavelength, multi-dimensional character of these data sets requires the development and use of generalized multi-variate methods that could be applied to other astronomical data. This project is the basis of a doctoral thesis; it will fully engage the funded graduate student and therefore contribute to the training of the next generation of scientists.