Collaborative Research: Submillimeter Studies of the Cosmological Star Formation and AGN Histories

AST-0084816Cowie，Lennox L.宇宙恒星形成和活动星系核历史的亚毫米研究这项工作的目标是分析最近在夏威夷15米James Clark Maxwell望远镜(JCMT)上用亚毫米普通用户测辐射热计阵列(Scuba)发现的关于高红移时被尘埃遮挡的恒星形成和活动星系核活动的新信息。该项目的科学家们计划扩大他们的观测范围，以涵盖流量范围在0.5到20mJy的亚毫米波长源的星系计数。他们预计，这些低通量源将构成远红外背景中所看到的大部分光。他们将使用来自VLA的深厘米射电地图和来自钱德拉卫星的高分辨率硬X射线图像来确定这些遥远的、严重被尘埃遮挡的来源的多波长特性。这些数据将被用来识别天体，以便用凯克、斯巴鲁和双子座望远镜进行进一步的研究。这些研究集中在我们今天看到的大多数恒星形成的宇宙时间间隔内星系的性质。在恒星形成的早期阶段，恒星被尘埃包裹，尘埃挡住了可见光。然而，能量很高的电磁辐射，如X射线，或极低能量的辐射，如亚毫米(远红外)或无线电波，可以穿透尘埃，使我们能够在恒星形成的时候“看到”它们。位于夏威夷15米JCMT的新开发的“Scuba”探测器可以用来探测非常微弱的亚毫米源，这可能是尘埃笼罩的恒星(恒星爆发)，也可能是活动星系核(AGN)，方法是利用中间的星系团来“透镜”或增强暗源的亮度。通过将这些观测与X射线区域的观测(来自钱德拉卫星)和射电区域的其他观测(使用VLA)相结合，考伊和巴格将能够从活动星系核中筛选出恒星爆发，并在演化的早期阶段确定这两种类型的活动对星系的相对重要性。该项目的资金由美国国家科学基金会的河外天文和宇宙学计划(AST/EXC)提供。

AST-0084816Cowie, Lennox L.Submillimeter Studies of the Cosmological Star Formation and AGN HistoriesThis work has as its goal the analysis of new information about the dust-obscured star formation and AGN activity at high-redshifts which was recently discovered with the Submillimeter Common User Bolometer Array (SCUBA) on the 15 m James Clark Maxwell Telescope (JCMT) in Hawaii. The project scientists plan to extend their observations to cover galaxy counts for sources in the flux range of 0.5 to 20 mJy at submillimeter wavelengths. They expect these low flux sources to comprise the bulk of the light seen in the far infrared background. They will use deep centimeter radio maps from the VLA and hi-resolution, hard x-ray images from the Chandra satellite to determine the multi-wavelength properties of these distant, heavily dust-obscured sources. This data in turn will be used to identify objects for further study with the Keck, Subaru, and Gemini telescopes.These studies focus on the properties of galaxies during an interval of cosmic time when most of the stars we see today were being formed. In the early stages of formation, stars are enshrouded in dust and this dust blocks visible light. However, very energetic electromagnetic radiation, such as X-rays, or very low energy radiation, such as submillimeter (far infrared) or radio waves can penetrate the dust and allow us to "see" the stars as they form. The newly developed "SCUBA" detector at the 15 m JCMT in Hawaii can be used to detect very faint submillimeter sources, which may be dust enshrouded stars (starbursts) or may be active galactic nuclei (AGNs), by using intervening clusters of galaxies to "lens", or enhance the brightness, of the faint sources. By combining these observations with ones in the X-ray region (from the Chandra satellite) and other observations in the radio region (using the VLA) Cowie and Barger will be able to sort out the starbursts from the AGNs and determine the relative importance of the two types of activity for galaxies in the early stages of evolution.Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***