Fast Transients and Furious Spectroscopy: Revealing the High-Speed Sky with Argus Pathfinder

新的传感器技术和大规模生产的光学系统将使阿格斯探路者项目的调查速度远远超过以往的任何望远镜，这将使新的发现成为可能。例如，超级耀斑是恒星非常快速的辐射爆发。了解超级耀斑的行为对于寻找地球以外的生命至关重要，这需要高速观测以及在事件发生时将多个望远镜快速指向事件的能力。其他神秘的快速事件已经在其他波长被观测到，它们有对应的可见光，可以揭示它们是什么。这些和其他的“瞬变”发生在天空中的随机时间和地点。捕捉它们的最好方法是尽可能多、尽可能快地观测天空。阿古斯探路者将制作一个大片天空的“电影”。它将观测数以千计的瞬变现象，并迅速向其他地面和太空望远镜发出警报。研究人员将致力于开发和升级莫尔黑德天文馆的主要时域天文学展览，以提高每年与展览互动的大约15万名学童的参与度和天文学灵感。2.3GPix的阿格斯探路者阵列覆盖了赤纬92度和赤经3.7度的天空条纹，1.4英寸/像素的采样几乎达到了大气观测极限。该系统跟踪天空的每条条纹15分钟，因此每晚几乎覆盖整个北方天空。探路者的CMOS探测器能够读取整个帧，只有毫秒级的开销，并具有1电子级的读取噪声，接近单光子探测能力。探路者的大型高速探测器阵列、宽通带和非常宽的视场结合在一起，使该系统能够在1秒持续时间内达到比最接近的同类搜索更高的数量级。在30秒的基础巡天中，探路者号将比之前能够覆盖整个天空的最好的探测器推进8个星等的深度，并且它将覆盖的调查区域至少是在大型望远镜上尝试的深而窄的分钟时间尺度探测器的5000倍。这些能力将使高速天空的全面特征和个体群体的详细天体物理测量成为可能，如快速射电暴和恒星超级耀斑。对于后者，探路者将获得时间分辨的光曲线和光谱，以模拟耀斑最重要的高能粒子释放，并限制它们对宜居性的影响。对于最大的耀斑，该系统将使用Swift卫星新的快速旋转能力来获得分钟时间尺度的直接EUV和x射线通量测量，从而直接测量潜在的行星可居住性影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

New sensor technologies and mass-produced optical systems will allow the Argus Pathfinder project to push to far faster survey speeds than any telescope before, which will enable new discoveries. For example, superflares are very fast bursts of radiation from stars. Understanding superflare behavior is crucial to the search for life beyond Earth, and it requires high-speed observations and the ability to point multiple telescopes very rapidly to events as they occur. Other mysterious fast events have been seen at other wavelengths, and they have visible-light counterparts that can shed light on what they are. These and other “transients” occur at random times and places in the sky. The best way to catch them is to survey as much of the sky as possible, as quickly as possible. Argus Pathfinder will make a “movie” of a very large patch of sky. It will observe thousands of transients as they evolve, and rapidly alert other ground- and space-based telescopes. The investigators will contribute to developing and upgrading the Morehead Planetarium’s major time-domain astronomy exhibit to improve the engagement and astronomical inspiration of the approximately 150,000 schoolchildren who interact with the exhibit each year. The 2.3GPix Argus Pathfinder array covers a stripe of the sky 92 degrees in declination and 3.7 degrees in right ascension, with 1.4”/pixel sampling almost reaching the atmospheric-seeing limit. The system tracks each stripe of the sky for 15 minutes, and thus covers almost the entire Northern sky each night. Pathfinder’s CMOS detectors are capable of reading out entire frames with only millisecond-level overheads and have 1-electron-level readnoise, which comes close to single-photon detection capabilities. Pathfinder’s large high-speed detector array, wide passband, and very wide field of view combine to make the system capable of reaching orders of magnitude beyond the closest comparable searches for 1-second duration transients. In the 30s-cadence base survey, Pathfinder will push eight magnitudes deeper than the best previous probes capable of covering the entire sky, and it will cover a survey area at least 5,000 times larger than the deep, narrow minute-timescale probes attempted on larger telescopes. These capabilities will enable a comprehensive characterization of the high-speed sky – and detailed astrophysical measurements of individual populations such as fast radio bursts and stellar superflares. For the latter, Pathfinder will obtain time-resolved light curves and spectra to model the flares’ all-important energetic particle releases and constrain their habitability impacts. For the largest flares, the system will use the new rapid-slew capabilities of the Swift satellite to obtain minute-timescale direct EUV and X-ray flux measurements, and thus a direct measurement of potential planetary habitability impacts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.