Collaborative Proposal: Through the Gas Darkly: Birth and Death in the Milky Way

AST020655帮助银河系中大多数恒星的诞生和死亡都是在光学望远镜的遮盖下进行的。厘米级的无线电波和硬X射线可以穿透模糊我们视线的气体和尘埃，但之前所有搜索的有限角分辨率和灵敏度让我们通过气体黑暗地凝视，试图建立一个关于银河系恒星形成和消亡的普查。哥伦比亚大学的David Helfand博士和加州大学戴维斯分校的Robert Becker博士将利用甚大阵列(VLA)对银河系平面进行新的调查，以及广泛的光学和近红外后续观测，以补充目前正在使用XMM-牛顿卫星进行的新的硬X射线银河面调查。该小组的所有观测(批准和建议的X射线和射电波长)都是非专有的，他们打算遵循第一个调查模式创建一个公共网站，一旦建立和核实所有缩小的图像就可以使用。因此，调查将为任何从事银河系天文学工作的天文学家提供有用的数据库。然而，这些研究人员已经确定了他们打算关注的一些具体问题：完整的银河系超新星遗迹普查，大质量恒星形成的普查，以及吸积动力双星系统完整样本的定义。这些调查将为银河系中大质量恒星的形成打开一扇新的窗口。所有由质量大于B0的恒星提供动力的HII区域将被银河系另一侧的太阳圈清楚地看到，因为射电源与在MSX卫星的飞机中红外地图上探测到的红外辐射一致；此外，在XMM-牛顿地图上将可以检测到其中许多恒星形成复合体，从而提供与X射线吸收柱密度的距离估计。该小组将在MDM 2.4米望远镜上安装一台新的红外相机，跟踪所有HII区域的候选者。结果将是迄今为止对银河系中大质量恒星形成的最完整的普查。从XMM牛顿图像对选定的X射线点源样本进行广泛的光学和近红外跟踪得到的几类X射线瞬变和稳定双星的光度函数将扩展2-3个数量级，比现有数据所允许的要弱2-3个数量级，为近双星演化和吸积模型提供了重要的新约束。由于已经分配了X射线和射电观测时间，通过MDM 2.4米望远镜上的新8K光学相机和近红外成像器/光谱仪，以及访问Lick和Keck天文台，这些研究人员拥有了提供银河系惊人新景象的资源。***

AST 020655HelfandThe majority of stellar births and stellar deaths in the Milky Way take place shrouded fromthe view of optical telescopes. Centimeter radio waves and hard X-rays can penetrate the gas anddust which obscure our vision, but the limited angular resolution and sensitivity of all previoussearches has left us peering through the gas darkly in an attempt to construct a census of starformation and demise in the Galaxy. Drs. David Helfand, at Columbia University, and Robert Becker, at the University of California at Davis, will carry out a new survey of the Galactic Plane with the Very Large Array (VLA), as well as extensive optical and near-infrared follow up observations, to complement a new hard X-ray Galactic plane survey now underway using the XMM-Newton satellite. All of this group's observations (approved and proposed, at X-ray and radio wavelengths) are nonproprietary, and they intend to follow the FIRST survey model in creating a public website which will make available all reduced images as soon as they are constructed and verified. Thus, thesurvey will provide databases of use to any astronomer working in Galactic astronomy. However,these researchers have identified a number of specific problems on which they intend to focus: a complete census of Galactic supernova remnants, a census of massive star formation, and the definition of complete samples of accretion-powered binary systems. The surveys will open a new window on massive star formation in the Milky Way. All HII regions powered by stars more massive than B0 will be clearly visible to the solar circle on the opposite side of the Galaxy as radio sources coincident with infrared emission detected in the MSX satellite mid-infrared maps of the plane; in addition, many of these star formation complexes will be detectable in the XMM-Newton maps, providing a distance estimate from the X-ray absorption column density. This group will follow up all HII region candidates with a new infrared camera on the MDM 2.4m telescope. Theresult will be the most complete census yet of massive star formation in the Galaxy. Luminosity functions for several classes of X-ray transients and steady binaries, derived from extensive optical and near-infrared follow up of selected samples of X-ray point sources from the XMM Newtonimages, will extend 2-3 orders of magnitude fainter than existing data allow, providing important new constraints on close-binary evolution and models for accretion. With both X-ray and radio observing time already allocated, with a new 8K optical camera and a near-infrared imager/spectrometer on the MDM 2.4m telescope and access to the Lick and Keck Observatories, these researchers have the resources in place to provide a striking new view of the Milky Way. ***