Star Formation in the Whole Orion Region

利用4度物镜光谱对猎户座区域的h - α发射线恒星进行了搜索。我们已经探测到多达1200颗发射恒星和一些发射物体。对外区域的调查结果已发表（文件五）。虽然外区巡天的极限星等没有我们以前在内区巡天的极限星等那么深，但发射线星分布的边界已经大致确定。我们用近红外光度法、光谱学、x射线成像等方法对其中的几十颗进行了后续观测，发现许多发射线星都是年轻的前主序星。对发射线星与OB星的空间分布进行了比较。我们现在正在准备总结观测结果的论文。在猎户座地区对赫比格-哈罗天体的搜索也发现了许多候选者。

A search for H-alpha emission-line stars in the Orion region was done using 4-degree objective prism spectra. We have been detected as many as 1200 emission stars and several emission objects. The survey results for the outer region has been published (paper V). Although the limiting magnitude of the survey of the outer region is not so deep compared with our previous surveys in the inner region, the boundary of the distribution of emission-line stars is roughly determined. We have made follow-up observations for some tens of them by NIR photometry, optical spectroscopy, and X-ray imaging, and found that many of emission-line stars are young pre-main sequence stars. The spatial distribution of emission-line stars are compared with that of OB stars. We are now preparing the papers for summarize our observational results. A search for Herbig-Haro objects in the Orion region have also made, and found many candidates.