标题： PIONIER：VLTI的4望远镜观测仪器 显示英文标题

标题： PIONIER: a 4-telescope visitor instrument at VLTI

摘要： PIONIER代表精密集成光学近红外成像实验。它使用集成光学合束器将四个1.8米辅助望远镜或四个8米单元望远镜（欧洲南方天文台，智利）结合在一起。该仪器自2009年12月起在IPAG集成，并于2010年10月在帕拉纳尔天文台进行调试。自2010年11月起，它开始提供科学观测数据。在本文中，我们详细介绍了仪器概念，描述了标准操作模式和数据减少策略。我们展示了典型性能并讨论了如何提高它们。本文基于在IPAG集成期间获得的实验室数据，以及在VLTI调试期间收集的天空数据。我们展示了PIONIER在双星deltaSco和HIP11231上的成像能力。PIONIER在H波段提供6个可见度和3个独立闭合相位，无论是宽带模式还是低光谱色散（R=40）模式，使用自然光（即非偏振光）。在分散模式下，1.8米辅助望远镜在中等大气条件下（视宁度<1"，tau0>3ms）的极限星等为Hmag=7。我们证明了闭合相位的精度为0.5度。校准可见度的精度根据大气条件从3%到15%不等。PIONIER已作为访客仪器安装并成功测试用于VLTI。它允许以前所未有的灵敏度进行高角分辨率成像研究。2011年3月四台8米单元望远镜的成功组合证明VLTI已准备好进行四望远镜操作。 显示英文摘要

摘要： PIONIER stands for Precision Integrated-Optics Near-infrared Imaging ExpeRiment. It combines four 1.8m Auxilliary Telescopes or four 8m Unit Telescopes of the Very Large Telescope Interferometer (ESO, Chile) using an integrated optics combiner. The instrument has been integrated at IPAG starting in December 2009 and commissioned at the Paranal Observatory in October 2010. It provides scientific observations since November 2010. In this paper, we detail the instrumental concept, we describe the standard operational modes and the data reduction strategy. We present the typical performance and discuss how to improve them. This paper is based on laboratory data obtained during the integrations at IPAG, as well as on-sky data gathered during the commissioning at VLTI. We illustrate the imaging capability of PIONIER on the binaries deltaSco and HIP11231. PIONIER provides 6 visibilities and 3 independent closure phases in the H band, either in a broadband mode or with a low spectral dispersion (R=40), using natural light (i.e. unpolarized). The limiting magnitude is Hmag=7 in dispersed mode under median atmospheric conditions (seeing<1", tau0>3ms) with the 1.8m Auxiliary Telescopes. We demonstrate a precision of 0.5deg on the closure phases. The precision on the calibrated visibilities ranges from 3 to 15% depending on the atmospheric conditions. PIONIER has been installed and successfully tested as a visitor instrument for the VLTI. It permits high angular resolution imaging studies at an unprecedented level of sensitivity. The successful combination of the four 8m Unit Telescopes in March 2011 demonstrates that VLTI is ready for 4-telescope operation.