NIRC2-Pol：凯克II望远镜近红外偏振测量的首光
NIRC2-Pol: First Light of Near-Infrared Polarimetry on Keck II
AI总结：
该研究介绍了凯克II望远镜新升级的NIRC2-Pol偏振模式，展示其独特能力及首幅AB Aurigae原行星盘的L'波段偏振图像，该图像更清晰呈现原行星盘螺旋臂。
AI中文摘要：
凯克II望远镜上的近红外相机2（NIRC2）近期完成了一套全新偏振观测模式的升级，这套新偏振模式被命名为NIRC2-Pol，为诸多新研究方向打开了大门，包括系外行星、银心、活动星系核及太阳系天体的研究。此次升级带来的新模式覆盖1.1至4.1微米波段（即J至L'波段），涵盖成像偏振测量、日冕仪成像偏振测量和光谱偏振测量。NIRC2-Pol具有独特性：凯克II是配备自适应光学（AO）馈送红外偏振测量能力的最大望远镜（10米），也是少数具备L'波段偏振成像能力的望远镜之一，更是唯一同时拥有偏振模式和涡旋日冕仪的望远镜。本文介绍NIRC2-Pol的设计、能力及当前运行状态，还展示其首次在轨结果：AB Aurigae原行星盘的首批L'波段偏振图像，这些图像比此前的L'波段总强度成像更清晰地揭示了该盘标志性的螺旋臂结构。
英文摘要：
NIRC2, the Near Infrared Camera 2 on the Keck II telescope, was recently upgraded with a new suite of polarimetric observing modes. The new polarimetry modes (referred to as NIRC2-Pol) open up a wide range of new studies, including investigations of exoplanets, the Galactic center, active galactic nuclei, and solar system objects. The new modes enabled by the upgrade span the 1.1 to 4.1 micron range (i.e. J through L' bands) and include imaging polarimetry, coronagraphic imaging polarimetry, and spectropolarimetry. NIRC2-Pol is unique, as Keck II is the largest telescope (10 m) on which AO-fed infrared polarimetry capabilities are available, one of few with L' polarimetric imaging, and the only one where there is both a polarimetric mode and a vortex coronagraph. Here, we introduce the design of NIRC2-Pol, its capabilities, and its current operational status. We also present its first on-sky results: the first L' polarimetric images of the AB Aurigae circumstellar disk. These images more clearly reveal the disk's iconic spiral arms than previous L' total intensity imaging.
