The Asteroid Terrestrial impact Last Alert System (ATLAS) system consists of two 0.5m Schmidt telescopes with cameras covering 29 square degrees at plate scale of 1.86 arcsec per pixel. Working in tandem, the telescopes routinely survey the whole sky visible from Hawaii (above $\delta > -50^{\circ}$) every two nights, exposing four times per night, typically reaching $o < 19$ magnitude per exposure when the moon is illuminated and $c < 19.5$ per exposure in dark skies. Construction is underway of two further units to be sited in Chile and South Africa which will result in an all-sky daily cadence from 2021. Initially designed for detecting potentially hazardous near earth objects, the ATLAS data enable a range of astrophysical time domain science. To extract transients from the data stream requires a computing system to process the data, assimilate detections in time and space and associate them with known astrophysical sources. Here we describe the hardware and software infrastructure to produce a stream of clean, real, astrophysical transients in real time. This involves machine learning and boosted decision tree algorithms to identify extragalactic and Galactic transients. Typically we detect 10-15 supernova candidates per night which we immediately announce publicly. The ATLAS discoveries not only enable rapid follow-up of interesting sources but will provide complete statistical samples within the local volume of 100 Mpc. A simple comparison of the detected supernova rate within 100 Mpc, with no corrections for completeness, is already significantly higher (factor 1.5 to 2) than the current accepted rates.

中文翻译：

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ATLAS瞬态科学服务器的设计与运行

小行星陆地撞击最后警报系统 (ATLAS) 系统由两个 0.5m 施密特望远镜组成，相机覆盖 29 平方度，板块尺度为每像素 1.86 弧秒。这些望远镜协同工作，每两晚定期对夏威夷可见的整个天空（高于 $\delta > -50^{\circ}$）进行一次观测，每晚曝光四次，通常每次曝光达到 $o < 19 $ 星等月亮被照亮，在黑暗的天空中每次曝光 $c < 19.5$。正在智利和南非建造另外两个单元，这将导致从 2021 年开始每天的全天节奏。ATLAS 数据最初设计用于探测潜在危险的近地物体，使一系列天体物理时域科学成为可能。从数据流中提取瞬态需要一个计算系统来处理数据，同化时间和空间中的探测，并将它们与已知的天体物理来源联系起来。在这里，我们描述了用于实时产生干净、真实、天体物理瞬变流的硬件和软件基础设施。这涉及机器学习和增强决策树算法，以识别河外和银河瞬变。通常我们每晚检测 10-15 个超新星候选者，我们会立即公开宣布。ATLAS 的发现不仅可以快速跟踪感兴趣的来源，而且可以在 100 Mpc 的本地体积内提供完整的统计样本。对 100 Mpc 内检测到的超新星速率进行简单比较，没有对完整性进行修正，已经明显高于当前接受的速率（因子 1.5 到 2）。