Radio and Infrared Studies of Star Formation in Galaxies

摘要：本课题的目标是获得6 ~ 12个具有明亮射电连续发射的1 cm附近星系的红外方阵谱图、Keck望远镜10微米和20微米的观测数据以及VLA在1和2cm的合成图像。这些将用于研究这些天体中恒星形成区域的辐射。这些数据将为未来地面（阿塔卡马大型毫米波阵列和南极推断观测）和深空（SOFIA/SIRTF）调查提供实质性基础，其中10微米区域将红移到100微米。恒星形成的一种戏剧性模式是星暴，在这种模式下，恒星的形成似乎是通过大的星团进行的，而不是像目前在银河系中形成的稀疏的疏散星团。这些“超级星团”很可能是球状星团的前身。银河系中的球状星团都很古老，有迹象表明，早期的宇宙可能更倾向于形成这些大型星团。超级星团的形成可以通过观察最年轻的大恒星形成区域来研究，这些区域最接近它们的诞生条件。这些区域通常在视觉上被尘埃和气体云遮挡。这个项目的目标是在红外和无线电波段探测附近星系的恒星形成，那里的星团和星云不像在可见光波段那样受到消光的影响。使用甚大阵列射电望远镜进行自由-自由射电连续体观测将用于绘制围绕年轻恒星的射电星云。隐藏的星云也可以通过被这些星团发出的强烈星光加热的尘埃发出的中红外辐射来发现。利用凯克望远镜，附近的恒星爆发将在中红外分辨率下成像，足以区分气态星云和年轻的星团。第一步是在附近的星系中找到最年轻的超级星团，在那里它们相对容易研究。这是本研究的主要目标。最终，一旦这些星团及其星云的位置确定，星云附近气体云的成像将显示星团与其出生气体的关系，这可能会揭示恒星形成的触发因素。这是一个可以用未来的阿塔卡马大型毫米波阵列望远镜进行富有成效的探索的主题。本项目由美国国家科学基金会星系外天文学和宇宙学项目（AST/EXC）资助

ABSTRACTAST- 0071276TurnerThe goal of this project is to obtain IR Brackett-line spectroscopy, 10-micron and 20-micron observations using the Keck telescope, and VLA synthesis images at 1 and 2cm for between 6 and 12 nearby galaxies which have bright radio continuum emission at 1 cm. These will be used to study the emission from star-forming regions in these objects. The data will provide a substantive base for the interpretation of future ground-based (the Atacama Large Millimeter Array and inferred observations from the South Pole) and deep, space-based (SOFIA/SIRTF ) surveys where the 10 micron region will be redshifted to100 microns.A dramatic mode of star formation is the starburst, in which star formation appears to proceed via large clusters rather than the sparse open clusters that currently form in the Milky Way. These "super star clusters" are likely precursors to globular clusters. Globular clusters in the Milky are all old, and there are indications that the early universe may have preferred to form these large clusters. The formation of super star clusters can be studied by observing the very youngest large star-forming regions, which are closest to their birth conditions. These regions are usually visually obscured by dust and gas clouds. The goal of this project is the detection of star formation in nearby galaxies in the infrared and radio wavelengths where star clusters and nebulae are not as affected by extinction as they are in the visible. Free-free radio continuum observations with the Very Large Array radio telescope will be used to map out radio nebulae surrounding young stars. Hidden nebulae can also be revealed by the mid-infrared emission from dust warmed by intense starlight from these clusters. With the Keck Telescope, nearby starbursts will be imaged in the mid-infrared at resolutions sufficient to distinguish gaseous nebulae from young star clusters. The first step is to locate the youngest super star clusters in nearby galaxies, where they are relatively easy to study. This is the major goal of this research. Eventually, once the locations of these clusters and their nebulae have been established, the imaging of gas clouds near the nebulae will show the relation of the clusters to their natal gas, which may reveal the trigger for the star formation. This is a topic that can be fruitfully explored with the future Atacama Large Millimeter Array telescope. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***