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Macau Periodical Index (澳門期刊論文索引)
- Author
- Ren, Yan-Qiong; Lu, Xiao-Ping; Luo, Tao; Mei, Bao
- Title
- An improved rotational period fitting method based on Baysian generalized lomb-scargle periodogram
- Journal Name
- 澳門科技大學學報
- Pub. Info
- Dec. 2017, Vol.11, No.1/2, pp. 111-118
- Link
- http://lib.must.edu.mo/sites/default/files/assets/images/Duu/2017%E5%B9%B4%E5%90%88%E5%88%8A%20%E6%BE%B3%E9%96%80%E7%A7%91%E6%8A%80%E5%A4%A7%E5%AD%B8%E5%AD%B8%E5%A0%B1.pdf
- Keyword
- Frequency；Rotation period；Polynomial fitting；Least squares method
- Abstract
- Abstract : Estimating the rotational period is generally the first step in analyzing astronomical observation data. Based on Bayesian probability theory, Mortier et al. (2015) proposed a method, called Baysian generalized Lomb-Scargle periodogram (BGLS), to describe the distribution of probability and present a full sine function with the specific frequency in the data. Compared with non-Bayesion method, BGLS can better recover the frequencies. However, BGLS is not stabling for searching rotational periods, especially in the case of the unevenly observation time interval. In this artical we apply the polynomial series to fit the points fold with the possible solutions by BGLS. Subsequently, a new defined merit function is also presented for estimating the derived periods and refining the best-fit result. Finally, the whole process to search the rotational period from the time series data is introduced. Furthemore, its application to the Palomar Transient Factory Survey (PTF) observation data confirms that the new method extended from BGLS can perform more stably and accurately. Paragraph Headings: 1. BGLS Periodogram and Related Technology 1.1. BGLS Periodogram 1.2. Polynomial Fitting 1.3. Newton's Method 2. Algorithm and Experiment 2.1. Algorithm 2.2. Simulated Example 2.3. Application for Asteriod 57303 3. Conclusions Tables: 1. Possible periods and corresponding x2 by BGLS 2. Periods and corresponding x2 searched by four kinds of methods Figures: 1. Newton's method 2. Stimulated Lightcurves 3. Rotational periods searched by BGLS for stimulated lightcurves 4. Rotational periods searched by improved BGLS for stimulated lightcurves 5. Lightcurves of asteriod 57303 observed in different time periods 6. Rotational periods searched by BGLS for asteriod 57303. From the upper-left to the lower-right panels are points folded with searched periods separated in 0-1 hours, 1-2 hours, 2-3 hours, 3-4 hours and 4-5 hours. The x-axis is time and the y-axis is brightness. 7. Rotational periods searched by BGLS for asteriod 57303. From the upper-left to the lower-right panels are points folded with searched periods separated in 5-6 hours, 6-7 hours, 7-8 hours, 8-9 hours and 9-10 hours. The x-axis is time and the y-axis is brightness. 8. Ten figures correspond to ten subfigures in Fig. 6 and Fig. 7 9. Cellinoid shape model 10. The relationship of periods and X2 11. The best period folded lightcurves of asteroid 57303, the blue points are original dara and rhe red points are fitting points.