标题： 斯必泽/红外阵列相机对猎户座分子云的调查 显示英文标题

标题： A Spitzer/IRAC Survey of the Orion Molecular Clouds

摘要： 我们展示了利用斯皮策空间望远镜上的红外阵列相机（IRAC）对猎户座A和B分子云进行的调查的初步结果。 该调查覆盖了总计5.6平方度的区域，灵敏度足以检测年龄为1百万年的氢燃烧极限以下的天体。 这些观测涵盖了多个已知的恒星形成区域，从猎户星云和NGC 2024中的大质量恒星形成簇，到L1641中的小质量恒星群。 我们将IRAC测光数据与2MASS点源目录中的测光数据结合，并利用得到的七波段数据来识别由于尘埃盘和包层导致的红外过量的恒星。 利用红外过量的存在作为年轻恒星的指示器，我们展示了这两个分子云中年轻恒星和原恒星的分布情况。 我们发现，大约一半的恒星位于围绕猎户云中两个最近的大质量恒星形成区域NGC 2024和猎户星云的致密星团中。 显示英文摘要

摘要： We present initial results from a survey of the Orion A and B molecular clouds made with the InfraRed Array Camera (IRAC) onboard the Spitzer Space Telescope. This survey encompasses a total of 5.6 square degrees with the sensitivity to detect objects below the hydrogen burning limit at an age of 1 Myr. These observations cover a number of known star forming regions, from the massive star forming clusters in the Orion Nebula and NGC 2024, to small groups of low mass stars in the L1641. We combine the IRAC photometry with photometry from the 2MASS point source catalog and use the resulting seven band data to identify stars with infrared excesses due to dusty disks and envelopes. Using the presence of an infrared excess as an indicator of youth, we show the distribution of young stars and protostars in the two molecular clouds. We find that roughly half of the stars are found in dense clusters surrounding the two regions of recent massive star formation in the Orion clouds, NGC 2024 and the Orion Nebula.