RAPID Opportunity for U/V band stellar imaging using intensity interferometry with the VERITAS Observatory

干涉测量学是一种将来自多个望远镜的光组合在一起，以产生具有极高空间分辨率的图像的方法。仅靠这两个望远镜都无法获得这样的敏锐度。这项具有挑战性的技术可以分辨太阳系外的恒星，尽管它们距离非常远。这样的壮举对于任何单一的望远镜来说都是不可能的，对它来说，即使是最近的恒星也仍然被视为未分辨的光点。普通干涉术将光学望远镜信号的幅度组合在一起形成图像。这个项目使用了另一种干涉测量法，它利用了光(光子)的量子性质。这种量子方法最早是在1950年的《S》中被证明的。Kieda和他的合作者通过使用大型的、分离良好的光学光收集器和快速、现代的电子设备来更新这种方法。在为期一年的观测过程中，它们将形成35颗明亮恒星的图像。他们将使用Veritas天文台和他们自己的专用探测器、电子设备和数据连接。该项目将作为超高分辨率光学天文学新体制的技术先驱。该项目将使用汉伯里-布朗-特维斯(HBT)干涉测量学的方法对紫外光/光学带通中的恒星进行成像。这种方法利用了强度波动之间的相关性，也称为光子聚束，当不同的探测器观察到相同的光源时，就会发生这种关联。在这种方法中，强度相关时间序列是根据其得出图像的干涉量。这种方法的主要优点是对大气湍流具有较强的鲁棒性，但其固有的低灵敏度要求大面积集光器。它还需要快速的时间分辨率和较长的积分时间。1960年S和1970年S利用HBT进行了天文观测，在此期间，以1ms的分辨率测量了30多颗恒星的角直径。这种方法最近在几颗明亮的恒星上进行了演示，这些恒星配备了现代探测器和工作在光子计数区域的电子设备。Kieda和他的合作者将使用Veritas伽马射线天文台望远镜来演示强度干涉成像。他们已经验证了测量黑体辐射空间和时间聚束的关键技术。他们已经展示了使用合成数据重建图像的能力。他们的方法要求从距基线约100米的多个探测器采集数据的亚纳秒同步。该项目有可能展示一种可扩展的技术，并为超高分辨率的天文光学成像开辟一个广阔的、尚未探索的前沿。

Interferometry is a method for combining the light from multiple telescopes to generate an image with exceptionally high spatial resolution. Such acuity cannot be obtained by either telescope alone. This challenging technique can resolve stars outside our solar system, despite their very great distances. Such a feat is impossible with any single telescope, for which even the closest stars are still seen as unresolved points of light. Ordinary interferometry combines the amplitudes of optical telescope signals to form an image. This project utilizes another kind of interferometry that makes use of the quantum nature of light (photons). This quantum approach was first demonstrated in the 1950?s. Kieda and collaborators update this approach by using large, well-separated optical light collectors and fast, modern electronics. They will form images of 35 bright stars over the course of a one-year observing campaign. They will use the VERITAS Observatory and their own dedicated detectors, electronics and data connectivity. This project will serve as a technology pathfinder that may lead to a new regime in ultra-high resolution optical astronomy.This project will image stars in the UV/Optical bandpass using the method of Hanbury Brown Twiss (HBT) interferometry. This method utilizes the correlation between intensity fluctuations, also called photon bunching, that occurs when different detectors observe the same source. In this method, the intensity correlation time series is the interferometric quantity upon which images are derived. The main advantage of this method is that it is robust to atmospheric turbulence; however, its low inherent sensitivity demands large-area light collectors. It also requires fast time resolution and long integration times. Astronomical observations using HBT were done in the 1960?s and 1970?s during which time the angular diameters of more than 30 stars were measured with a resolution of 1 mas. This method was recently demonstrated on several bright stars with modern detectors and electronics operating in the photon-counting regime. Kieda and collaborators will use the VERITAS gamma-ray observatory telescopes to demonstrate imaging with intensity interferometry. They have validated key technologies for measuring spatial and temporal bunching of blackbody radiation. They have demonstrated the ability to reconstruct images using synthetic data. Their method requires sub-nanosecond synchronization of the data acquisition from multiple detectors spaced at ~100+ meter baselines. This project has the potential to demonstrate a scalable technology and open a wide, unexplored frontier for astronomical, optical imaging with ultra-high resolution.