Periodicity in the continua and broad line curves of a quasar E1821+643

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• 作者：A. Kovačević ; L. Č. Popović ; A. I. Shapovalova ; D. Ilić
• 关键词：(Galaxies) quasars ; supermassive black holes ; Methods ; data analysis
• 刊名：Astrophysics and Space Science
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：362
• 期：2
• 全文大小：
• 刊物类别：Physics and Astronomy
• 刊物主题：Astrophysics and Astroparticles; Astronomy, Observations and Techniques; Cosmology; Space Sciences (including Extraterrestrial Physics, Space Exploration and Astronautics); Astrobiology;
• 出版者：Springer Netherlands
• ISSN：1572-946X
• 卷排序：362

文摘

Here we present an in-depth analysis of the periodicity of the continua and broad emission lines of a quasar E1821+643. We applied non-parametric composite models, the linear sum of stationary and non-stationary Gaussian processes, and quantified contribution of their periodic parts. We found important qualitative differences among the three periodic signals. Periods of \({\sim}2200\) and \({\sim}4500\) days appear in both continua 5100 Å and 4200 Å, as well as in the \(\mathrm{H}\upgamma\) emission line. Their integer ratio is nearly harmonic \({\sim}\frac{1}{2}\), suggesting the same physical origin. We discuss the nature of these periods, proposing that the system of two objects in dynamical interaction can be origin of two largest periods.