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Related papers: Characterizing the Optical Variability of Bright B…

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Blazars are known to exhibit variability across a broad range of timescales. This behavior can include periodicity in their $\gamma$-ray emission, whose clear detection remains an ongoing challenge, partly due to the inherent stochasticity…

High Energy Astrophysical Phenomena · Physics 2025-07-08 P. Peñil , M. Ajello , S. Buson , A. Domínguez , J. R. Westernacher-Schneider , A. Rico , S. Adhikari , J. Zrake

We present the time variability properties of a sample of six blazars, AO 0235+164, 3C 273, 3C 279, PKS 1510-089, PKS 2155-304, and 3C 454.3, at optical-IR as well as gamma-ray energies. These observations were carried out as a part of the…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Ritaban Chatterjee , C. Bailyn , E. W. Bonning , M. Buxton , P. Coppi , G. Fossati , J. Isler , L. Maraschi , C. M. Urry

Aims: We aim at investigating the time-behaviour of a sample of gamma-ray blazars. We present the results from a 13 month-long optical photometry monitoring campaign of the blazars PKS 0048-097, PKS 0754+100, HB89 0827+243, PKS 0851+202,…

Linear time series analysis, mainly the Fourier transform based methods, has been quite successful in extracting information contained in the ever-modulating light curves (Lcs) of active galactic nuclei, and thereby contribute in…

High Energy Astrophysical Phenomena · Physics 2021-01-06 Gopal Bhatta , Radim Pánis , Zdeněk Stuchlík

We present cross-correlation studies of gamma-ray (0.1-300 GeV), X-ray (0.2-10 keV) and optical (R-band) variability of a sample of 26 blazars during 2008-2016. The light curves are from Fermi-LAT, Swift-XRT, and the Yale-SMARTS blazar…

High Energy Astrophysical Phenomena · Physics 2020-04-08 Anwesh Majumder , Kaustav Mitra , Ritaban Chatterjee , C. M. Urry , C. D. Bailyn , Prantik Nandi

We study the gamma-ray variability of 13 blazars observed with the Fermi Large Area Telescope (LAT). These blazars have the most complete light curves collected during the first 4 years of the Fermi sky survey. We model them with the…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Malgorzata A. Sobolewska , Aneta Siemiginowska , Brandon C. Kelly , Krzysztof Nalewajko

Blazars, a subset of powerful active galactic nuclei, feature relativistic jets that shine in a broadband electromagnetic radiation, e. g. from radio to TeV emission. Here I present the results of the studies that explore gamma-ray and…

High Energy Astrophysical Phenomena · Physics 2022-10-18 Gopal Bhatta

This paper presents light curves and the first systematic characterization of variability of the 106 objects in the Fermi Large Area Telescope (LAT) Bright AGN Sample (LBAS). Weekly light curves obtained during the first 11 months of survey…

High Energy Astrophysical Phenomena · Physics 2015-05-18 A. A. Abdo

We present results from four years of twice-weekly 15 GHz radio monitoring of about 1500 blazars with the Owens Valley Radio Observatory 40 m telescope. Using the intrinsic modulation index to measure variability amplitude, we find that,…

High Energy Astrophysical Phenomena · Physics 2014-01-16 Joseph L. Richards , Talvikki Hovatta , Walter Max-Moerbeck , Vasiliki Pavlidou , Timothy J. Pearson , Anthony C. S. Readhead

Blazars present highly variable $\gamma$-ray emission. This variability, which can range from a few minutes to several years, is also observed at other wavelengths across the entire electromagnetic spectrum. We make use of the first 12…

High Energy Astrophysical Phenomena · Physics 2024-03-05 P. Peñil , J. Otero-Santos , M. Ajello , S. Buson , A. Domínguez , L. Marcotulli , N. Torres-Albà , J. Becerra González , J. A. Acosta-Pulido

Using blazar light curves from the optical All-Sky Automated Survey for Supernovae (ASAS-SN) and the $\gamma$-ray \textit{Fermi}-LAT telescope, we performed the most extensive statistical correlation study between both bands, using a sample…

High Energy Astrophysical Phenomena · Physics 2023-01-18 T. de Jaeger , B. J. Shappee , C. S. Kochanek , J. T. Hinkle , S. Garrappa , I. Liodakis , A. Franckowiak , K. Z. Stanek , J. F. Beacom , J. L. Prieto

We discuss the time-series behavior of 8 extragalactic 3FGL sources away from the Galactic plane (i.e., $\mid b\mid \geq 10^{\circ}$) whose uncertainty ellipse contains a single X-ray and one radio source. The analysis was done using the…

High Energy Astrophysical Phenomena · Physics 2021-07-14 P. Nkundabakura , J. D. Kamanzi , J. D. Mbarubucyeye , T. Mutabazi

The gamma-ray emission of blazar jets shows a pronounced variability and this feature provides limits to the size and to the speed of the emitting region. We study the gamma-ray variability of bright blazars using data from the first 18…

High Energy Astrophysical Phenomena · Physics 2015-05-28 T. Sbarrato , L. Foschini , G. Ghisellini , F. Tavecchio

We investigate the variability properties of blazars in the GeV band using the data of the Fermi/LAT telescope. We find that blazars exhibit variability on the scales down to the minimal timescale resolvable by Fermi, which is a function of…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Ievgen Vovk , Andrii Neronov

We present long term optical and near infrared flux variability analysis of 37 blazars detected in the $\gamma$-ray band by the {\it Fermi Gamma-Ray Space Telescope}. Among them, 30 are flat spectrum radio quasars (FSRQs) and 7 are BL Lac…

High Energy Astrophysical Phenomena · Physics 2020-08-28 P. Z. Safna , C. S. Stalin , Suvendu Rakshit , Blesson Mathew

We used the data from the Fermi Gamma-ray Space Telescope to characterise the {\gamma}-ray flux variability of blazars on month-like time scales. Our sample consists of 1120 blazars of which 481 are flat spectrum radio quasars (FSRQs) and…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Bhoomika Rajput , C. S. Stalin , Suvendu Rakshit

Decade-long monitoring of blazars at optical and infrared (OIR) wavelengths with the Small and Moderate Aperture Research Telescope System (SMARTS) in Chile and in $\gamma$-rays with the Fermi Large Area Telescope (LAT) has enabled the…

High Energy Astrophysical Phenomena · Physics 2021-07-14 M. Polkas , M. Petropoulou , G. Vasilopoulos , A. Mastichiadis , M. C. Urry , P. Coppi , C. Bailyn

We study the ensemble optical variability of 276 FSRQs and 86 BL Lacs in the Palomar-QUEST Survey with the goal of searching for common fluctuation properties, examining the range of behavior across the sample, and characterizing the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Anne Bauer , Charles Baltay , Paolo Coppi , Nancy Ellman , Jonathan Jerke , David Rabinowitz , Richard Scalzo

We present an in-depth and systematic variability study of a sample of 20 powerful blazars, including 12 BL Lacs and 8 flat spectrum radio quasars, applying various analysis tools such as flux distribution, symmetry analysis, and time…

High Energy Astrophysical Phenomena · Physics 2020-03-18 Gopal Bhatta , Niraj Dhital

In this study, we conducted a systematic analysis of long-term Fermi-LAT \gamma-ray data for a sample of blazars, including FSRQs, BL\,Lacs, and BCUs, to investigate their $\gamma$-ray variability. We focused on light curves binned in 3-,…

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