Near Infrared, High Resolution Observations Using Laser Guide Adaptive Optics System

本计画研究的目的是为日本国立天文台位于夏威夷夏威夷岛的8.2米斯巴鲁望远镜开发一套新的“雷射导引自适应光学系统”，以促进对遥远星系的高解析度、近红外线观测，所开发的新自适应光学系统包括一个188元件波前感测器、一个188元件驱动变形镜及控制系统。该系统通过对一颗亮导星星的真实的实时测量，评估湍流大气产生的波前误差的变化，并驱动变形镜对这些误差进行真实的实时补偿，实现斯巴鲁望远镜衍射极限成像能力。2006年10月进行的第一次光实验表明，在大气湍流下，0.6角秒的恒星图像可以压缩成0.06角秒的图像大小，比不使用现有系统获得的图像小10倍。这有助于提高空间分辨率 ...更多信息 激光制导星星产生系统是研制成功的另一个关键系统。它包括与RIKEN合作开发的全固态4W和频激光器，光子晶体光纤将高功率激光传输到安装在斯巴鲁望远镜顶端的50厘米直径激光发射望远镜。2006年10月进行的第一次激光发射实验也证明成功地在离地面90公里的钠层中产生了一颗人造激光引导星星，在那里，调谐在589 nm钠D2线的激光束激发了钠原子，并导致钠光的发射，亮度足以测量大气湍流。同时，目前的PI发现了一个红移为7.0的星系，它被证明是最遥远的（因此也是宇宙历史上最早的）星系。该项目小组的目标是对这些星系进行高分辨率成像观测，以揭示早期宇宙中星系的形成和演化。少

This project research aimed at developing newly a "laser guided adaptive optics system" for the 8.2m Subaru Telescope at Mauna Kea, Hawaii Island, operated by National Astronomical Observatory of Japan to promote high resolution, near infrared observations of distant galaxies.The new adaptive optics system developed comprises of a 188-element wavefront sensor, a 188-driving element deformable mirror, and the control system. The system measures a bright guide star in real time to evaluate variation of the wavefront error produced by the turbulent atmosphere and drives the deformable mirror to compensate those errors in real time to achieve diffraction limited imaging capability of the Subaru Telescope. The first light experiment conducted in October 2006 has shown that a stellar image of 0.6 arcsec under the atmospheric turbulence can be squeezed into a 0.06 arcsec image size, 10times smaller than that obtained without using the current system. This helps much in improving the spatial r … More esolution and the sensitivity of observations.Another key system developed is a laser guide star generating system. It comprises of an all solid-state 4W sum-frequency laser developed in collaboration with the RIKEN, a photonic crystal optical fiber to transmit the high power laser to the 50cm diameter laser launching telescope mounted at the top end of the Subaru Telescope. First laser launching experiment carried out in October 2006 also proved successful in generating an artificial laser guide star in the sodium layer at 90km above the ground where the laser beam tuned at 589nm sodium D2 line excites the sodium atoms and causes emission of sodium light bright enough to measure the atmospheric turbulence.In the meantime the current PI found a galaxy at redshift 7.0, which turned out to be the most distant (and hence the earliest in the cosmic history) galaxy. The project team aims to make high resolution imaging observations of these galaxies to unrabel the formation and evolution of galaxies in the early universe. Less