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Related papers: Kepler light curve analysis of the blazar W2R 1926…

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We analyzed Kepler light curves of the blazar W2R 1926+42 that provided nearly continuous coverage from quarter 11 through quarter 17 (589 days between 2011 and 2013) and examined some of their flux variability properties. We investigate…

Astrophysics of Galaxies · Physics 2018-05-01 Yutong Li , Shaoming Hu , Paul J. Wiita , Alok C. Gupta

We performed variability analysis of the multiwavelength light curves for the flat-spectrum radio quasar PKS 0727-11. Using the generalized Lomb-Scargle periodogram, we identified a possible quasi-periodic oscillation (QPO) of $\sim$ 168.6…

High Energy Astrophysical Phenomena · Physics 2025-02-28 Yuncai Shen , Tingfeng Yi , Vinit Dhiman , Lisheng Mao , Liang Dong

We analyze the ${\it Kepler}$ monitoring light curve of a blazar W2R 1926$+$42 to examine features of microvariability by means of the "shot analysis" technique. We select 195 intra-day, flare-like variations (shots) for the continuous…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Mahito Sasada , Shin Mineshige , Shinya Yamada , Hitoshi Negoro

We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with ~0.2% errors, 30 minute sampling and >90% duty cycle, showing numerous delta I/I > 25% flares over timescales as short as…

High Energy Astrophysical Phenomena · Physics 2014-09-08 R. Edelson , R. Mushotzky , S. Vaughan , J. Scargle , P. Gandhi , M. Malkan , W. Baumgartner

Using an unprecedented cadence of 30 minutes provided by the Transiting Exoplanet Survey Satellite (TESS), we have examined the optical light curves (LCs) of the blazar S5 0716+714 obtained from its Sectors 40, 47, and 53 over a period of…

High Energy Astrophysical Phenomena · Physics 2026-03-09 Shubham Kishore , Alok C. Gupta , Paul J. Wiita

Blazars show rapid and violent variabilities, which timescale are often less than a day. We studied intraday variations by applying a shot analysis technique to Kepler monitoring of blazar W2R 1926+42 in Quarter 14. We obtained a mean…

High Energy Astrophysical Phenomena · Physics 2015-02-10 M. Sasada , S. Mineshige , S. Yamada , H. Negoro

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

We selected a sample of 24 XMM-Newton light curves (LCs) of four high energy peaked blazars, PKS 0548-322, ON 231, 1ES 1426+428 and PKS 2155-304. These data comprise continuous light curves of 7.67h to 18.97h in length. We searched for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Haritma Gaur , Alok C. Gupta , Pawel Lachowicz , Paul J. Wiita

In this work we search for signatures of low-dimensional chaos in the temporal behavior of the Kepler-field blazar W2R 1946+42. We use a publicly available, ~160000 points long and mostly equally spaced, light curve of W2R 1946+42. We apply…

High Energy Astrophysical Phenomena · Physics 2015-03-18 Rumen Bachev , Banibrata Mukhopadhyay , Anton Strigachev

We conducted a comprehensive variability analysis of the blazar PKS 2255-282 using Fermi-LAT observations spanning over four years, from MJD 57783.5 to 59358.5. Our analysis revealed a transient quasi-periodic oscillation (QPO) with a…

High Energy Astrophysical Phenomena · Physics 2024-08-26 Ajay Sharma , Anuvab Banerjee , Avik Kumar Das , Avijit Mandal , Debanjan Bose

We detected a possible quasi-periodic oscillation (QPO) of ~ 71 days in the 0.1 -- 300 GeV gamma-ray Fermi-LAT light curve of the high redshift flat spectrum radio quasar B2 1520+31. We identify and confirm that quasi-period by Lomb Scargle…

High Energy Astrophysical Phenomena · Physics 2019-02-27 Alok C. Gupta , Ashutosh Tripathi , Paul J. Wiita , Pankaj Kushwaha , Zhongli Zhang , Cosimo Bambi

We present time series analyses of the full Kepler dataset of Zw 229-15. This Kepler light curve --- with a baseline greater than three years, composed of virtually continuous, evenly sampled 30-minute measurements --- is unprecedented in…

High Energy Astrophysical Phenomena · Physics 2014-10-14 Rick Edelson , Simon Vaughan , Matt Malkan , Brandon Kelly , Krista Smith , Padi Boyd , Richard Mushotzky

We report the detection ($>4\sigma$) of a Quasi-Periodic Oscillation (QPO) in the $\gamma$-ray light curve of 3C 454.3 along with a simultaneous marginal QPO detection ($>2.4\sigma$) in the optical light curves. Periodic flux modulations…

High Energy Astrophysical Phenomena · Physics 2020-12-23 Arkadipta Sarkar , Alok C. Gupta , Varsha R. Chitnis , Paul J. Wiita

We carried out a high time-resolution, multicolour optical observing campaign for eight $\gamma$-ray detected blazars during 2010-2020. We analyze flux variations, correlations between magnitudes and colours on different timescales.…

High Energy Astrophysical Phenomena · Physics 2023-02-15 X. Chang , T. F. Yi , D. R. Xiong , C. X. Liu , X. Yang , H. Z. Li , Y. L. Gong , W. W. Na , Y. Li , Z. H. Chen , J. P. Chen , L. S. Mao

We report the first results of a systematic investigation to characterize blazar variability power spectral densities (PSDs) at optical frequencies using densely sampled (5--15 minutes integration time), high photometric accuracy…

High Energy Astrophysical Phenomena · Physics 2021-03-10 Arti Goyal

We present the results of the power spectral density (PSD) analysis for the blazars Mrk\,421 and PKS\,2155$-$304, using good-quality, densely sampled light curves at multiple frequencies, covering 17 decades of the electromagnetic spectrum,…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Arti Goyal

Variability is a typical observation feature of Fermi blazars, sometimes it shows quasi-periodic oscillation (QPO). In this work, we obtained 5-day binned light curves (with a time coverage of $\sim$ 12.9 yr) for S5 1044+71 based on Fermi…

High Energy Astrophysical Phenomena · Physics 2022-04-27 G. G. Wang , J. T. Cai , J. H. Fan

The continued observations of Sw J1644+57 in X-ray and radio bands accumulated a rich data set to study the relativistic jet launched in this tidal disruption event. The X-ray light curve of Sw J1644+57 from 5-30 days presents two kinds of…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Jiu-Zhou Wang , Wei-Hua Lei , Ding-Xiong Wang , Yuan-Chuan Zou , Bing Zhang , He Gao , Chang-Yin Huang

We present results of a periodicity search of 20 intra-day variable optical light curves of the blazar S5 0716+714, selected from a database of 102 light curves spanning over three years. We use a wavelet analysis technique along with a…

Astrophysics · Physics 2008-12-18 Alok C. Gupta , A. K. Srivastava , Paul J. Wiita

The cataclysmic variable MV Lyr was present in the Kepler field yielding a light curve with the duration of almost 1500 days with 60 second cadence. Such high quality data of this nova-like system with obvious fast optical variability show…

Solar and Stellar Astrophysics · Physics 2020-01-08 A. Dobrotka , H. Negoro , S. Mineshige
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