演講資訊

Prof. Yu-Yen Chang (張雨晏 助理教授) (Dept. of Physics at National Chung Hsing University)

"Identifying AGN host galaxies by Machine Learning"

時間/地點: 2020-09-18 14:00 [S4-1013]

摘要:

We use machine learning techniques to investigate active galaxies, including X-ray selected AGNs (XAGNs), infrared selected AGNs (IRAGNs), and radio selected AGNs (RAGNs). Using known physical parameters in the Cosmic Evolution Survey (COSMOS) field, we are able to have well-established training samples in the ultra-deep regions of Hyper Suprime-Cam (HSC) survey. We compare several Python packages (e.g., scikit-learn, Keras, and XGBoost), and use XGBoost to identify AGNs and show the performance (e.g., accuracy, precision, recall, F1-score, and AUROC). Our results indicate that the performance is high for bright XAGN and IRAGN host galaxies. HSC (optical) information with Wide-field Infrared Survey Explorer (WISE) band-1 and WISE band-2 (near-infrared) information perform well to identify AGN hosts. For both type-1 (broad-line) XAGNs and type-1 (unobscured) IRAGNs, the performance is very good by using optical to infrared information. These results can apply to the five-band data from the wide regions of the HSC survey, and future all-sky surveys.

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