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arXiv 2107.06290astro-ph.IM
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单碟望远镜高效率亚毫米波spectroscopy的数据科学去噪方法

A data-scientific noise-removal method for efficient submillimeter spectroscopy with single-dish telescopes

Akio Taniguchi, Yoichi Tamura, Shiro Ikeda, Tatsuya Takekoshi, Ryohei Kawabe

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30 pages, 11 figures, 6 tables, accepted for publication in AJ
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摘要：

对于使用地基单碟望远镜的亚毫米光谱学，消除来自地球大气和仪器的噪声贡献是必不可少的。为此，我们提出了一种基于数据科学方法的新方法。其关键技术是统计矩阵分解，自动分离的天文发射线的信号从漂移噪声成分的快速采样（1- 10 Hz）的时间序列谱的位置切换（PSW）观测获得。由于所提出的方法不应用两组噪声数据之间的减法（即，源上和源外光谱），它将观测灵敏度提高了$\sqrt{2}$倍。它还减少了人为信号，如频谱上的基线波纹，这也可能有助于提高有效灵敏度。我们证明了这一改进，通过使用光谱数据的发射线对高红移星系观察与2毫米接收器上的50米大毫米望远镜（LMT）。由于所提出的方法是离线进行的，不需要额外的测量，它提供了一个即时的改进，减少到目前为止，与传统的方法的光谱。它还可以实现由未来50米级大型亚毫米单碟望远镜驱动的高效深度光谱学，其中通过机械天线或反射镜驱动的快速PSW观测难以实现。

英文摘要：

For submillimeter spectroscopy with ground-based single-dish telescopes, removing noise contribution from the Earth's atmosphere and the instrument is essential. For this purpose, here we propose a new method based on a data-scientific approach. The key technique is statistical matrix decomposition that automatically separates the signals of astronomical emission lines from the drift noise components in the fast-sampled (1--10 Hz) time-series spectra obtained by a position-switching (PSW) observation. Because the proposed method does not apply subtraction between two sets of noisy data (i.e., on-source and off-source spectra), it improves the observation sensitivity by a factor of $\sqrt{2}$. It also reduces artificial signals such as baseline ripples on a spectrum, which may also help to improve the effective sensitivity. We demonstrate this improvement by using the spectroscopic data of emission lines toward a high-redshift galaxy observed with a 2-mm receiver on the 50-m Large Millimeter Telescope (LMT). Since the proposed method is carried out offline and no additional measurements are required, it offers an instant improvement on the spectra reduced so far with the conventional method. It also enables efficient deep spectroscopy driven by the future 50-m class large submillimeter single-dish telescopes, where fast PSW observations by mechanical antenna or mirror drive are difficult to achieve.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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