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Related papers: Study of periodic signals from blazars

200 papers

Quasi-periodic oscillations (QPO) originating from innermost regions of blazars can provide unique perspective of some of the burning issues in blazar studies including disk-jet connection, launch of relativistic jets from the central…

High Energy Astrophysical Phenomena · Physics 2019-06-12 Gopal Bhatta

Blazars exhibit variable emission on diverse timescales. Some light curves show signs of quasiperiodic oscillations (QPOs), which may encode clues regarding the physical processes behind the emission or point to supermassive binary black…

High Energy Astrophysical Phenomena · Physics 2026-02-24 M. A. Hashad , A. Hammad , Amr A. EL-Zant

Search for periodic signals from blazars has become widely discussed topic in recent years. In the scenario that such periodic changes originate from the innermost regions of blazars, the signals bear imprints of the processes occurring…

High Energy Astrophysical Phenomena · Physics 2018-12-03 Gopal Bhatta

A comprehensive analysis of quasi-periodic oscillations (QPOs) in the gamma-ray emissions of blazars. Utilizing 15 years of Fermi-LAT observations of seven blazars in our sample, we identify both long-term and transient quasi-periodic…

High Energy Astrophysical Phenomena · Physics 2025-05-30 Ajay Sharma , Sakshi Chaudhary , Aishwarya Sarath , Debanjan Bose

We present a study on the detection and characterization of transient quasi-periodic oscillations (QPOs) in the $\gamma$-ray emission of blazars 4C +31.03, MG1 J123931+0443, and PKS 1622$-$253. Using light curves derived from \textit{Fermi}…

High Energy Astrophysical Phenomena · Physics 2025-12-11 P. Penil , J. Otero-Santos , A. Circiello , A. Banerjee , S. Buson , A. Rico , M. Ajello , S. Adhikari

Detection of periodicity in the broad-band non-thermal emission of blazars has so far been proven to be elusive. However, there are a number of scenarios which could lead to quasi-periodic variations in blazar light curves. For example,…

We investigate the possible presence of quasi-periodic oscillation (QPO) signals in 2103 blazars from the Zwicky Transient Facility (ZTF) time-domain survey. We detect a low-frequency QPO signal in five blazars observed over these…

Astrophysics of Galaxies · Physics 2023-10-05 Anuvab Banerjee , Vibhore Negi , Ravi Joshi , Nagendra Kumar , Paul J. Wiita , Hum Chand , Nikita Rawat , Xue-Bing Wu , Luis C. Ho

Microquasars are the compact objects generally including accreting black holes which produce relativistic jets. The physical mechanisms of jet launching, collimation, and acceleration are poorly understood. Microquasars show strong…

High Energy Astrophysical Phenomena · Physics 2025-04-08 Wei Wang

This work presents possible quasi-periodic oscillations in the Transiting Exoplanet Survey Satellite observations of blazars that are in the 157-month hard X-ray survey done by Swift's Burst Alert Telescope. We report observations from four…

High Energy Astrophysical Phenomena · Physics 2025-12-15 Ashutosh Tripathi , Paul J. Wiita , Krista Lynne Smith

This study explores transient quasi-periodic oscillations (QPOs) in the $\gamma$-ray emission of two blazars, PMN J0531$-$4827 and PKS 1502+106, using over a decade of Fermi Large Area Telescope observations. The analysis focuses on…

High Energy Astrophysical Phenomena · Physics 2025-08-20 P. Penil , J. Otero-Santos , A. Banerjee , S. Buson , A. Rico , M. Ajello , S. Adhikari

In this work, we analyzed the long term gamma-ray data by a Fermi Large Area Telescope (Fermi-LAT) of blazar S2 0109+22, ranging from 2008 to 2023. The quasi-periodic oscillations (QPOs) of blazars aided in investigating the physical…

High Energy Astrophysical Phenomena · Physics 2023-07-17 Haoyang Zhang , Fan Wu , Benzhong Dai

This study explores the detection of Quasi-Periodic Oscillations (QPOs) in blazars as a method to identify kink events within their jets, utilizing both $\gamma$-ray and polarized light observations. Focusing on a sample of 9 blazars, we…

High Energy Astrophysical Phenomena · Physics 2025-04-15 P. Peñil , H. Zhang , J. Otero-Santos , M. Ajello , S. Buson , S. Adhikari , A. Rico , J. Escudero Pedrosa , I. Agudo , D. Morcuende , A. Sota , V. Casanova , F. J. Aceituno

The fascination with the blazar OJ 287 stems not only from its status as a prominent candidate for a close supermassive black hole (SMBH) binary, but also because of the thermal bremsstrahlung origin proposed for its giant optical…

High Energy Astrophysical Phenomena · Physics 2024-08-14 Gopal-Krishna

While there has been an increase in interest in the possibility of quasi-periodic oscillations (QPOs) in blazars, the search has hitherto been restricted to sources with well-sampled light curves. Objects with light curves that include gaps…

High Energy Astrophysical Phenomena · Physics 2024-09-18 M. A. Hashad , Amr A. El-Zant , Y. Abdou , H. M. Badran

Black hole and neutron star X-ray binary systems routinely show quasi-periodic oscillations (QPOs) in their X-ray flux. Despite being strong, easily measurable signals, their physical origin has long remained elusive. However, recent…

High Energy Astrophysical Phenomena · Physics 2021-06-30 Adam Ingram , Sara Motta

Transient quasi-periodic oscillations (QPOs) are extremely interesting observational phenomena. However, the precise physical mechanisms leading to their generation are still hotly debated. We performed a systematic search for transient QPO…

High Energy Astrophysical Phenomena · Physics 2024-10-01 Junping Chen , Jinjie Yu , Weitian Huang , Nan Ding

The dynamics and instability of the magnetized jets connected to jet acceleration are complicated and are not yet well understood. Quasi-periodic oscillations (QPOs) as special timing features in black hole systems can directly probe…

High Energy Astrophysical Phenomena · Physics 2026-03-09 Jiashi Chen , Pengfu Tian , Wei Wang

Blazars are a sub-population of quasars whose jets are nearly aligned with the line-of-sight, which tend to exhibit multi-wavelength variability on a variety of timescales. Quasi-periodic variability on year-like timescales has been…

High Energy Astrophysical Phenomena · Physics 2018-09-05 A. Miguel Holgado , Alberto Sesana , Angela Sandrinelli , Stefano Covino , Aldo Treves , Xin Liu , Paul Ricker

Study of quasi-periodic oscillations (QPO) in blazars is one of the crucial methods for gaining insights into the workings of the central engines of active galactic nuclei. QPOs with various characteristic time scales have been observed in…

High Energy Astrophysical Phenomena · Physics 2023-03-08 Banerjee , Anuvab , Sharma , Ajay , Mnadal , Avijit , Das , Avik Kumar , Bhatta , Gopal , Bose , Debanjan

The discovery of quasi-periodic oscillations (QPOs) in magnetar giant flares has opened up prospects for neutron star asteroseismology. However, with only three giant flares ever recorded, and only two with data of sufficient quality to…

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