Linking Galactic and Extragalactic Star Formation

令人惊讶的是，与宇宙中的其他星系相比，我们对银河系的全球恒星形成知之甚少。这是因为太阳位于平坦的银河系盘中，而且几乎所有恒星的形成都发生在这个盘中。在天空中，这个圆盘看起来像一个相对较薄的带，在这个带内可以找到各种距离的恒星。这个项目将把这条光带分解成一个三维地图，目的是了解我们银河系的全球恒星形成。这张图将允许我们区分区域的亮度（观测属性）和它们的光度（固有属性）。该团队将通过测量所有已知的大质量恒星形成区域的红外和无线电波长的亮度来绘制三维地图，并将使用无线电观测将红外和无线电亮度转化为光度。当地的高中生将协助观察，为西弗吉尼亚州的学生提供重要的研究机会。PI和他的学生将把衍生光度的分布与其他星系的光度分布进行比较，以确定我们所生活的星系的类型。他们还将估算出银河系正在形成的恒星数量。这些结果将帮助我们更好地了解银河系的恒星形成过程。银河系和星系外的天文学家之间严重缺乏交流，因为没有银河系恒星形成区域的完整样本可以与外部星系的恒星形成区域进行比较。该团队将通过使用无线电重组线观测，创建一个由单个o型星电离的所有银河系HII区域的目录来解决这个问题。当地的高中生将帮助进行观察，为西弗吉尼亚州的学生提供重要的科学机会。这些观测结果将允许我们使用旋转曲线模型从观测到的径向速度计算运动距离。该团队将通过定位具有相似径向速度和可能相似距离的HII区域集群来补充距离，并将使用人口综合模型调整目录偏差。PI和他的学生将在8微米到21厘米的波长范围内得到HII区域的通量，并利用目录距离将这些通量转化为光度。他们将研究在对HII区域亮度函数（LF）的研究中发现的三个星系外结果：在一些星系中看到的银河系LF的断裂，“集群”和“分布式”HII区域LF具有不同形状的发现，以及星系LF形状与哈勃类型之间的相关性。然后，银河系的总光度可以通过将所有目录HII区域的光度相加来计算。然后，银河系的总光度将通过星系外恒星形成速率校准转换成恒星形成速率。

It is surprising how little we know about global star formation in our Milky Way Galaxy compared to other galaxies in the Universe. This is because the Sun lies in the flat Milky Way disk and because nearly all star formation occurs within this disk. Looking at the sky, the disk appears as a relatively thin band, with stars at all distances found within this band. This project will disentangle this band of light into a three-dimensional map with the aim of understanding the global star formation in our Galaxy. This map will allow us to differentiate between the brightness of regions (an observed property) with their luminosities (an intrinsic property). The team will create the three-dimensional map by measuring the brightness of all known massive star formation regions at infrared and radio wavelengths, and will use radio observations to turn the infrared and radio brightnesses into luminosities. Local high school students will assist in the observations, providing vital research opportunities for the students of West Virginia. The PI and his students will compare the distribution of derived luminosities with that of other galaxies to determine the type of galaxy we live in. They will also estimate how many stars our Galaxy is forming. These results will help us to better understand star formation in our Galactic home.There is a severe lack of communication between Galactic and extragalactic astronomers because there is no complete sample of Galactic star forming regions that can be compared to those of external galaxies. The team will solve this problem by creating a catalog of all Galactic HII regions ionized by single O-stars using radio recombination line observations. Local high school students will help with the observations, providing vital science opportunities for the students of West Virginia. These observations will allow us to compute kinematic distances from the observed radial velocities using a rotation curve model. The team will supplement the distances by locating clusters of HII regions that have similar radial velocities, and presumably similar distances, and will adjust for catalog biases using a population synthesis model. The PI and his students will derive HII region fluxes at wavelengths from 8 micron to 21 cm and turn these fluxes into luminosities using the catalog distances. They will investigate three extragalactic results found in studies of the HII region luminosity function (LF): the break in the Galactic LF seen in some galaxies, the finding that ''clustered'' and ''distributed'' HII-region LFs have different shapes, and the correlation between the galaxy's LF shape and its Hubble type. The total Milky Way luminosity can then be computed by summing the luminosities of all catalog HII regions. The total Milky Way luminosities will then be converted into star formation rates using extragalactic star formation rate calibrations.