ARIES-Institutional Digital Repository

Browsing by Author "Wiita, Paul J."

Browsing by Author "Wiita, Paul J."

Sort by: Order: Results:

  • Detection of a quasi-periodic oscillation in γ -ray light curve of the high-redshift blazar B2 1520+31 
    Gupta, Alok C.; Tripathi, Ashutosh; Wiita, Paul J. (Monthly Notices of the Royal Astronomical Society, 2019-02)
    We detected a possible quasi-periodic oscillation (QPO) of ∼71 d in the 0.1–300 GeV γ-ray Fermi-Large Area Telescope light curve of the high-redshift flat spectrum radio quasar B2 1520+31. We identify and confirm that ...
  • Detection of Quasiperiodic Oscillations in the Blazar S4 0954+658 with TESS 
    Kishore, Shubham; Gupta, Alok C.; Wiita, Paul J. (The Astrophysical Journal, 2023-01)
    We report the detection of several quasiperiodicities around 0.6–2.5 days in the optical emission of the blazar S4 0954+658. The source was observed by the Transiting Exoplanet Survey Satellite in six sectors and it ...
  • Intranight optical variability of blazars and radio-quiet quasars using the ZTF survey 
    Negi, Vibhore; Krishna, Gopal; Joshi, Ravi; Chand, Hum; Wiita, Paul J.; Navaneeth, P. K.; Singh, Ravi S. (Monthly Notices of the Royal Astronomical Society, 2023-07)
    We explore the potential of the ongoing Zwicky Transient Facility (ZTF) survey for studying intranight optical variability (INOV) of active galactic nuclei (AGNs), in particular for picking rare events of large INOV ...
  • Investigating the origin of optical flares from the TeV blazar S4 0954+65 
    Pandey, Ashwani; Bachev, Rumen; Czerny, Bo˙zena; Wiita, Paul J.; Gupta, Alok C.; Strigachev, Anton; Popowicz, Adam (Astronomy & astrophysics, 2023-11)
    Aims. We aim to investigate the extreme variability properties of the TeV blazar S4 0954+65 using optical photometric and polarisation observations carried out between 2017 and 2023 using three ground-based telescopes. Methods. ...
  • Multiband cross-correlated radio variability of the blazar 3C 279 
    Mohana A, Krishna; Gupta, Alok C.; Marscher, Alan P.; Sotnikova, Yulia V.; Jorstad, S. G.; Wiita, Paul J.; Cui, Lang; Aller, Margo F.; Aller, Hugh D.; Kovalev, Yu. A.; Kovalev, Y. Y.; Liu, Xiang; Mufakharov, T. V.; Popkov, A. V.; Mingaliev, M. G.; Erkenov, A. K.; Nizhelsky, N. A.; Tsybulev, P. G.; Tsybulev, P. G.; Zhao, Wei; Weaver, Z. R.; Morozova, D. A. (Monthly Notices of the Royal Astronomical Society, 2024-01)
    We present the results of our study of cross-correlations between long-term multiband observations of the radio variability of the blazar 3C 279. More than a decade (2008–2022) of radio data were collected at seven different ...
  • Multiband optical variability on diverse time-scales of the TeV blazar TXS 0506 + 056, the first cosmic neutrino source 
    Dhiman, Vinit; Gupta, Alok C.; Bachev, Rumen; Wiita, Paul J.; Cellone, Sergio A.; Strigachev, A.; Gaur, Haritma; Darriba, A.; Bisen, D. P.; Locatelli, G.; Mammana, L. A.; Semkov, E. (Monthly Notices of the Royal Astronomical Society, 2024-01)
    We report the first extensive optical flux and spectral variability study of the TeV blazar TXS 0506 + 056 on intranight to long-term time-scales using BVRI data collected over 220 nights between 2017 January 21 to 2022 ...
  • Multiwavelength Temporal Variability of the Blazar PKS 1510–089 
    Yuan, Q.; Kushwaha, Pankaj; Gupta, Alok C.; Tripathi, Ashutosh; Wiita, Paul J.; Zhang, M.; Liu, X.; Lähteenmäki, Anne; Tornikoski, Merja; Tammi, Joni; Ramakrishnan, Venkatessh; Cui, L.; Wang, X.; Gu, M. F.; Bambi, Cosimo; Volvach, A. E. (The Astrophysical Journal, 2023-08)
    We perform correlation and periodicity search analyses on long-term multiband light curves of the flat-spectrum radio quasar PKS 1510−089 observed by the space-based Fermi-Large Area Telescope in γ-rays, the SMARTS and ...
  • Optical Flux and Spectral Variability of the TeV Blazar PG 1553+113 
    Pandey, Ashwani; Gupta, Alok C.; Wiita, Paul J.; Tiwari, S. N. (The Astrophysical Journal, 2019-02)
    We present the results of our optical (VRI) observations of the TeV blazar PG 1553+113 over eight nights in 2016 April. We monitored the blazar quasi-simultaneously in V and R bands each night and examined the light ...
  • Optical intraday variability of the blazar S5 0716+714 
    Tripathi, Tushar; Gupta, Alok C.; Takey, Ali; Bachev, Rumen; Vince, Oliver; Strigachev, Anton; Kushwaha, Pankaj; Elhosseiny, E. G.; Wiita, Paul J.; Damljanovic, G.; Dhiman, Vinit; Fouad, A.; Gaur, Haritma; Gu, Minfeng; Hamed, G. E.; Kishore, Shubham; Kurtenkov, A.; Rastogi, Shantanu; Semkov, E.; Zead, I.; Zhang, Zhongli (Monthly Notices of the Royal Astronomical Society, 2024-01)
    We present an extensive recent multiband optical photometric observations of the blazar S5 0716+714 carried out over 53 nights with two telescopes in India, two in Bulgaria, one in Serbia, and one in Egypt during 2019 ...
  • Probable low-frequency quasi-periodic oscillations in blazars from the ZTF survey 
    Banerjee, Anuvab; Negi, Vibhore; Joshi, Ravi; Kumar, Nagendra; Wiita, Paul J.; Chand, Hum; Rawat, Nikita; Wu, Xue-Bing; Ho, Luis C. (Monthly Notices of the Royal Astronomical Society, 2023-12)
    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 ...
  • Quasi-simultaneous Optical Flux and Polarization Variability of the Binary Super Massive Black Hole Blazar OJ 287 from 2015 to 2023: Detection of an Anticorrelation in Flux and Polarization Variability 
    Gupta, Alok C.; Kushwaha, Pankaj; Valtonen, Mauri J.; Savchenko, Sergey S.; Jorstad, Svetlana G.; Imazawa, Ryo; Wiita, Paul J.; Gu, Minfeng; Marscher, Alan P.; Zhang, Zhongli; Bachev, Rumen; Borman, G. A.; Gaur, Haritma; Grishina, T. S.; Hagen-Thorn, V. A.; Kopatskaya, E. N.; Larionov, V. M.; Larionova, E. G.; Larionova, L. V.; Morozova, D. A.; Nakaoka, T; Strigachev, A; Troitskaya, Yulia V.; Troitsky, I. S.; Uemura, M.; Vasilyev, A. A.; Weaver, Z. R.; Zhovtan, A. V. (Astrophysical Journal Letters, 2023-11)
    We study the optical flux and polarization variability of the binary black hole blazar OJ 287 using quasi simultaneous observations from 2015 to 2023 carried out using telescopes in the USA, Japan, Russia, Crimea, ...
  • Rapid Optical Flares in the Blazar OJ 287 on Intraday Timescales with TESS 
    Kishore, Shubham; Gupta, Alok C.; Wiita, Paul J. (The Astrophysical Journal, 2024-01)
    We have analyzed the optical light curves of the blazar OJ 287 obtained with the Transiting Exoplanet Survey Satellite over about 80 days from 2021 October 13 to December 31, with an unprecedented sampling of 2 ...
  • Spectral energy distributions of the BL Lac PKS 2155 − 304 from XMM–Newton 
    Bhagwan, Jai; Gupta, A. C.; Papadakis, I. E.; Wiita, Paul J. (Oxford University Press, 2014-11-11)
    We have used all 20 archival XMM–Newton observations of PKS 2155 − 304 with simulta- neous X-ray and UV/optical data to study its long-term flux and spectral variability. We find significant variations, in all bands, on ...

Search ARIES-IDR

Browse

My Account