Asgard/NOTT 冷零差相机的状态与性能
Status and performance of the Asgard/NOTT cold nulling camera
- KU Leuven（荷语鲁汶大学）
- Fornax（福纳克斯研究所）
- University of Liège（列日大学）
- Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，匈牙利研究与教育网络天文学与地球科学研究中心）
- Australian National University（澳大利亚国立大学）
- Delft University of Technology（代尔夫特理工大学）
- University of Arizona（亚利桑那大学）
- University of Exeter（埃克塞特大学）
- Université Côte d’Azur（蔚蓝海岸大学）
- European Organisation for Astronomical Research in the Southern Hemisphere（欧洲南方天文台）
- Large Binocular Telescope Observatory（大型双筒望远镜天文台）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文介绍 Asgard/NOTT 冷零差相机的状态与性能，该相机用于 VLTI 首台零差干涉仪，以高对比度观测系外行星和尘埃，初步低温测试验证了其关键性能。
AI中文摘要：
长基线零差干涉测量技术抑制了恒星的轴上光，从而能够以高角分辨率对微弱的星周发射和系外行星进行高对比度观测。尘埃与行星零差观测（NOTT）仪器是 Asgard 仪器套件中的 L' 波段零差干涉仪，将成为甚大望远镜干涉仪（VLTI）上安装的首台零差干涉仪。其主要科学目标是表征位于近距离（<10 天文单位）轨道间隔处的热/暖黄道尘埃和类木星年轻系外行星，而间接探测方法在该距离上最为敏感。NOTT 使用一个四望远镜集成光学光子束组合器，工作波段为 3.5-4.0 微米。光子芯片产生光度、亮光和零差输出，这些输出经过偏振分光、光谱色散后，由 NOTT 冷零差相机成像到截止波长为 5 微米的 HAWAII-2RG 探测器上。冷光学组件包括光子芯片接口、注入光学元件、准直器、沃拉斯顿棱镜、色散元件、成像器和低温探测器级。机械实现设计为在约 90 K 温度下运行，采用铝制支撑结构、弹簧加载光学支架和低温兼容机构，以在冷却过程中保持对准。我们介绍了 NOTT 冷零差相机和低温恒温器组件的当前状态与性能。该系统正在进行组装、集成和验证，以验证热稳定性、探测器运行、真空性能和光机可重复性。初步低温测试已证明冷光学器件在接近 100 K、探测器在 30 K 下运行，滤光轮通过低温验证，真空压力达到 8 x 10^-8 毫巴。这些活动是 NOTT 作为 VLTI 首台零差干涉仪部署的关键一步。
英文摘要：
Long-baseline nulling interferometry suppresses the on-axis light of a star, enabling high-contrast observations of faint circumstellar emission and exoplanets at high angular resolution. The Nulling Observations of dusT and PlaneTs (NOTT) instrument is the L'-band nulling interferometer of the Asgard instrument suite and will be the first nuller installed at the Very Large Telescope Interferometer (VLTI). Its main scientific goals are to characterise hot/warm exozodiacal dust and young Jupiter-like exoplanets at close (<10 AU) orbital separations, where indirect detection methods are most sensitive. NOTT uses a four-telescope integrated-optics photonic beam combiner operating over 3.5-4.0 micrometres. The photonic chip produces photometric, bright, and nulled outputs that are polarization-split, spectrally dispersed, and imaged onto a 5-micrometre-cutoff HAWAII-2RG detector by the NOTT cold nulling camera. The cold optical assembly includes the photonic-chip interface, injection optics, collimator, Wollaston prism, dispersive element, imager, and cryogenic detector stage. The mechanical implementation is designed for operation near 90 K using aluminium support structures, spring-loaded optical mounts, and cryogenic-compatible mechanisms to preserve alignment during cooldown. We present the current status and performance of the NOTT cold nulling camera and cryostat assembly. The system is undergoing assembly, integration, and verification to validate thermal stability, detector operation, vacuum performance, and opto-mechanical repeatability. Initial cryogenic tests have demonstrated operation near 100 K for the cold optics and 30 K for the detector, cryogenic validation of the filter wheel, and a vacuum pressure of 8 x 10^-8 mbar. These activities represent a key step toward deploying NOTT as the first nulling interferometer at the VLTI.
