Unsupervised Method for Correlated Noise Removal for Multi-wavelength Exoplanet Transit Observations

作者:Dehghan Firoozabadi Ali; Diaz Alejandro; Rojo Patricio; Soto Ismael; Mahu Rodrigo; Becerra Yoma Nestor; Sedaghati Elyar
来源:Publications of the Astronomical Society of the Pacific, 2017, 129(977): 074502.
DOI:10.1088/1538-3873/aa70df

摘要

Exoplanetary atmospheric observations require an exquisite precision in the measurement of the relative flux among wavelengths. In this paper, we aim to provide a new adaptive method to treat light curves before fitting transit parameters in order to minimize systematic effects that affect, for instance, ground-based observations of exo-atmospheres. We propose a neural-network-based method that uses a reference built from the data itself with parameters that are chosen in an unsupervised fashion. To improve the performance of proposed method, K-means clustering and Silhouette criteria are used for identifying similar wavelengths in each cluster. We also constrain under which circumstances our method improves the measurement of planetary-to-stellar radius ratio without producing significant systematic offset. We tested our method in high quality data from WASP-19b and lowquality data from GJ-1214. We succeed in providing smaller error bars for the former when using JKTEBOP, but GJ-1214 light curve was beyond the capabilities of this method to improve as it was expected from our validation tests.

  • 出版日期2017-7-1