Blazar flaring patterns (B-FlaP) classifying blazar candidate of uncertain type in the third Fermi-LAT catalogue by artificial neural networks
Blazar flaring patterns (B-FlaP) classifying blazar candidate of uncertain type in the third Fermi-LAT catalogue by artificial neural networks
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DOI：
10.1093/mnras/stw1830
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发表时间：
2016-07
影响因子：
4.8
通讯作者：
G. Chiaro;D. Salvetti;G. L. Mura;M. Giroletti;D. Thompson;D. Bastieri
中科院分区：
文献类型：
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作者：
G. Chiaro;D. Salvetti;G. L. Mura;M. Giroletti;D. Thompson;D. Bastieri
费米大面积望远镜（LAT）是目前研究GeV$\gamma$射线天空最重要的设施。迄今为止，费米 LAT 已发现超过三千个 $\gamma$ 射线源。 1144 ($\sim40\%$) 个源是耀变体类的活动星系，573 ($\sim20\%$) 被列为不确定型候选耀变体 (BCU)，或没有结论性分类的源。当严格的多波长分析不可用时，我们使用经验累积分布函数 (ECDF) 和人工神经网络 (ANN) 来快速筛选和分类 BCU，该方法仅基于在 $\gamma$ 射线能量收集的数据。根据我们的方法，我们将 342 个 BCU 分类为 BL Lacs，154 个 BCU 分类为 FSRQ，而 77 个对象仍不确定。此外，无线电分析和地面光学天文台的直接观测被用作统计分类的对应部分来验证该方法。这种方法之所以引起人们的兴趣，是因为费米星表中未分类源的数量不断增加，而且耀变体，特别是其子类高同步加速器峰值（HSP）天体是大气切伦科夫望远镜的主要目标。
The Fermi Large Area Telescope (LAT) is currently the most important facility for investigating the GeV $\gamma$-ray sky. With Fermi LAT more than three thousand $\gamma$-ray sources have been discovered so far. 1144 ($\sim40\%$) of the sources are active galaxies of the blazar class, and 573 ($\sim20\%$) are listed as Blazar Candidate of Uncertain type (BCU), or sources without a conclusive classification. We use the Empirical Cumulative Distribution Functions (ECDF) and the Artificial Neural Networks (ANN) for a fast method of screening and classification for BCUs based on data collected at $\gamma$-ray energies only, when rigorous multiwavelength analysis is not available. Based on our method, we classify 342 BCUs as BL Lacs and 154 as FSRQs, while 77 objects remain uncertain. Moreover, radio analysis and direct observations in ground-based optical observatories are used as counterparts to the statistical classifications to validate the method. This approach is of interest because of the increasing number of unclassified sources in Fermi catalogs and because blazars and in particular their subclass High Synchrotron Peak (HSP) objects are the main targets of atmospheric Cherenkov telescopes.