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      https://www.ias.ac.in/article/fulltext/joaa/035/03/0489-0493

    • Keywords

       

      Galaxies: BL Lacertae objects; individual: BL Lacertae: broad-band spectral indices; periodic variation; methods: numerical: wavelet analysis.

    • Abstract

       

      BL Lacertae is one of the famous AGN that shows convincing evidence to support periodic variability. We compile R-band data and radio 22 GHz database from the available literature to build the light curves and to calculate broad-band spectral indices. This paper employs the wavelet periodic estimation method. The analysis results indicate that the most possible period is 7.02–7.36 yr in the selected wave-bands. The broad-band spectral indices have a possible period of 4.11 yr as a half value in selected wave-bands. The results confirm that the variability period in the radio 22 GHz is in agreement with the optical R band of about 7.01 yr, as also mentioned in other literatures.

    • Author Affiliations

       

      Hao-Jing Zhang1 2 Jing-Ming Bai1 Yu-Ying Bao3 Xiong Zhang2

      1. Yunnan Astronomical Observatory, National Astronomical Observatory, Chinese Academy of Science, Kunming, Yunnan 650011, China.
      2. College of Physics and Electronics, Yunnan Normal University, Kunming, Yunnan 650092, China.
      3. Department of Physics, Yuxi Teachers’ College, Yuxi, Yunnan 653100, China.
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