Probing the Low Surface Brightness Universe with Dragonfly

用蜻蜓号探测低表面亮度宇宙

• 批准号: RGPIN-2017-05989
• 负责人: Abraham, Roberto
• 金额: $ 7.87万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=692932
• 关键词: Probing; Low; Surface; Brightness; Universe

Over the past 40 years the cutting edge of astronomical imaging has transitioned from photographic plates on ground based telescopes to CCD detectors on space telescopes. This has improved our ability to detect small faint galaxies by about seven magnitudes (over a factor of 600). Over this same period of time there has been no improvement in our ability to detect large but faint (low surface brightness) structures in the Universe. This is because the limiting factor in this case is not photon statistics or image resolution, it is control of systematic errors, such as the scattering of light and sky variability. Working with a colleague at Yale, I recently developed a novel new telescope, the Dragonfly Telephoto Array, which has succeeded in breaking through this technical barrier and which is revealing the composition of the Universe at very faint surface brightness levels (Abraham g as the Milky Way but have only 1/100 1/1000 of its mass, and explaining how they survive in the very hostile environment of a galaxy cluster is a major puzzle that has become a highly active area of investigation in the last year. But these early results from Dragonfly are only the tip of the iceberg. It is now clear that the low surface brightness Universe is a treasure trove of almost totally unexplored astrophysical phenomena, and the race is now on to study these. In this proposal I describe a program of investigation whose goals are to: (1) explore the nature of dark matter in ultra-diffuse galaxies by determining their masses in galactic stellar halos; (2) test fundamental predictions of models for galaxy assembly by undertaking an ambitious wide-area survey of the low surface brightness sky; (3) determine the ultimate limits for the performance of the Dragonfly concept, in order to see if we can grow the system to the point that we can directly explore the "cosmic web" a predicted large-scale network of dark matter filaments believed to connect galaxies to each other.

过去 40 年来，天文成像的前沿技术已经从地面望远镜上的照相底片转变为太空望远镜上的 CCD 探测器。这使我们探测小型微弱星系的能力提高了约七个星等（超过 600 倍）。在同一段时间内，我们探测宇宙中大型但微弱（低表面亮度）结构的能力没有任何改善。这是因为这种情况下的限制因素不是光子统计或图像分辨率，而是系统误差的控制，例如光的散射和天空的变化。我最近与耶鲁大学的一位同事合作开发了一种新颖的望远镜，即蜻蜓长焦阵列，它成功地突破了这一技术障碍，并在非常微弱的表面亮度水平下揭示了宇宙的组成（亚伯拉罕g为银河系，但质量只有银河系的1/100 1/1000），解释它们如何在星系团的非常恶劣的环境中生存是一个主要难题，已成为一个高度活跃的领域 去年的调查。但蜻蜓的这些早期结果只是冰山一角。现在很清楚，低表面亮度的宇宙是几乎完全未经探索的天体物理现象的宝库，现在正在展开研究这些现象的竞赛。在这个提案中，我描述了一个研究计划，其目标是：（1）通过确定星系恒星晕中的质量来探索超漫射星系中暗物质的性质； (2) 通过对低表面亮度天空进行雄心勃勃的广域调查，测试星系组装模型的基本预测； （3）确定“蜻蜓”概念性能的最终极限，以便看看我们是否可以将系统发展到可以直接探索“宇宙网”的程度，“宇宙网”是一个预测的大规模暗物质细丝网络，据信可以将星系彼此连接起来。