Issue |
A&A
Volume 689, September 2024
|
|
---|---|---|
Article Number | A35 | |
Number of page(s) | 10 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202347593 | |
Published online | 30 August 2024 |
Quasi-periodic oscillation analysis for a sample of blazars at the optical band
1
Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, Shandong 264209, China
2
School of Space Science and Physics, Shandong University, 264209 Weihai, China
Received:
28
July
2023
Accepted:
15
April
2024
Context. Quasi-periodic behavior in the light curves of blazars can help us understand the physics. The identification of the supermassive black hole binary (SMBHB) is an active topic, and the periodicity analysis of light curves is a powerful method for searching for these sources.
Aims. In this work, we aim to identify quasi-periodic oscillations (QPOs) in the optical band light curves in our sample and discuss the possible physical origins behind these targets.
Methods. In this study, we collected 155 optical band light curves from three different monitoring programs. We searched for QPOs in our sample using the generalised Lomb-Scargle (GLS) and weighted wavelet Z-transform (WWZ) methods. We simulated 104 artificial light curves and evaluated the significance of the results using the Monte Carlo method.
Results. Our work reveals that 18 targets show QPOs with timescales ranging from 200 days to 1400 days. These QPOs could be explained by three scenarios, including the SMBHB, instability of thick disks and jet precession. Since the frequencies corresponding to QPOs are in the nHz regime, our work provides candidates of SMBHBs for further verification.
Key words: galaxies: active / BL Lacertae objects: general / galaxies: jets / quasars: general
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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