Studies of Star Formation with Galactic Plane Surveys

通过银河平面巡天研究恒星形成

• 批准号: 1009049
• 负责人: Mark Hemeon-Heyer
• 金额: $ 12.5万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1009049&HistoricalAwards=false
• 关键词: Studies; Star; Formation; Galactic; Plane

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.

该计划通过利用最近的银河平面巡天的丰富协同作用来研究恒星形成过程，这些巡天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，为银河系内盘中恒星形成的物理提供最完整的观测约束。特别是，研究了巨型分子云内的物理过程，该过程负责形成星团和OB恒星凝结的大块团块。数据集包括FCRAO（五所大学射电天文台）对12CO和13CO发射的勘测、Bolocam银河平面勘测（BGPS）、甚大阵列（VLA）银河平面勘测和斯皮策遗产计划多波段成像光度计 斯皮策内银河平面巡天（MIPSGAL）。通过将毫米波、尘埃和射电连续谱勘测中确定的源与 13CO 发射速度联系起来，人们可以获得银河系不同环境和位置的巨型分子云内恒星形成活动的测量结果。这些措施包括存在于大块团块中的云质量的分数、源自红外光度的恒星形成率，以及来自射电光度的莱曼-α连续光子的普查。将这些特性与源自 13CO 排放的母体分子云的动力学状态和速度结构进行比较。这些集体信息用于评估星际湍流和膨胀电离前沿驱动的冲击对调节恒星形成的作用。该项目的一部分是校准一组云的尺寸-速度色散关系系数，这些云的距离通过三角视差测量确定为优于 10%。然后，这种校准为银河系中的巨型分子云建立了一种新的距离测量，可以补充或改进从银河系旋转曲线得出的运动距离。在银河系中建立一种新的距离测量极大地有助于银河系结构的研究和单个恒星形成区域的研究。 项目期间，恒星形成区域的汇编可在网上获取。这些数据集的多波长、多维特征需要开发和使用可应用于其他天文数据的广义多变量方法。该项目是博士论文的基础；它将充分吸引受资助的研究生，从而为下一代科学家的培训做出贡献。