Zobrazeno 1 - 10
of 122
pro vyhledávání: '"Kushwaha, Pankaj"'
Autor:
Kushwaha, Pankaj
OJ 287 is one of the most dynamic BL Lacertae objects that has exhibited behaviour representative of the entire blazar class and is also one of the best sources with simultaneous multi-wavelength coordinated data. Motivated by strong X-ray variabilit
Externí odkaz:
http://arxiv.org/abs/2410.05783
Autor:
Zhou, Dongtao, Zhang, Zhongli, Gupta, Alok C., Kushwaha, Pankaj, Wiita, Paul J., Gu, Minfeng, Xu, Haiguang
Publikováno v:
2024MNRAS.532.3285Z
We present analyses of Suzaku XIS light curves and spectra of the BL Lac object OJ 287 with observations positioned primarily around proposed recurrent optical outbursts. The first two observations were performed in 2007 April 10 - 13 (epoch 1) and 2
Externí odkaz:
http://arxiv.org/abs/2408.02371
Autor:
Yadav, Sameer, Kushwaha, Pankaj
Publikováno v:
Galaxies 2024, 12(4), 34
The BL Lacertae (BL Lac) object OJ 287 underwent an intense X-ray activity phase, exhibiting its brightest recorded X-ray flare in 2016-2017, characterized by much softer X-ray spectra and, concurrently, its first-ever recorded very-high-energy (VHE)
Externí odkaz:
http://arxiv.org/abs/2407.07047
Autor:
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
We present an extensive recent multi-band 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 November -- 2022 December. We c
Externí odkaz:
http://arxiv.org/abs/2311.10358
Autor:
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.
Publikováno v:
Astrophysical Journal Letters, 957 (2023) L11 (11pp)
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, and Bulgaria. This is one of the mos
Externí odkaz:
http://arxiv.org/abs/2311.02372
Autor:
Pandey, Ashwani, Kushwaha, Pankaj, Wiita, Paul J., Prince, Raj, Czerny, Bozena, Stalin, C. S.
Transition blazars exhibit a shift from one subclass to the next during different flux states. It is therefore crucial to study them to understand the underlying physics of blazars. We probe the origin of the multi-wavelength emission from the transi
Externí odkaz:
http://arxiv.org/abs/2310.05096
Autor:
Yuan, Q., Kushwaha, Pankaj, Gupta, Alok C., Tripathi, Ashutosh, Wiita, Paul J., Zhang, M., Liu, X., Lahteenmaki, Anne, Tornikoski, Merja, Tammi, Joni, Ramakrishnan, Venkatessh, Cui, L., Wang, X., Gu, M. F., Bambi, Cosimo, Volvach, A. E.
We perform correlation and periodicity search analyses on long-term multi-band light curves of the FSRQ 1510-089 observed by the space-based Fermi--Large Area Telescope in gamma-rays, the SMARTS and Steward Observatory telescopes in optical and near-
Externí odkaz:
http://arxiv.org/abs/2306.10248
Autor:
Kushwaha, Pankaj
Optical-UV synchrotron spectrum has been argued to be the primary driver of the majority of X-ray spectral changes in the BL Lacertae object OJ 287 during its low and intermediate X-ray flux state. Here, we focus on the lowest recorded X-ray flux sta
Externí odkaz:
http://arxiv.org/abs/2305.16144
Autor:
Bachev, Rumen, Tripathi, Tushar, Gupta, Alok C., Kushwaha, Pankaj, Strigachev, Anton, Kurtenkov, Alexander, Nikolov, Yanko, Boeva, Svetlana, Damljanovic, Goran, Vince, Oliver, Stojanovic, Milan, Kishore, Shubham, Gaur, Haritma, Dhiman, Vinit, Fan, Junhui, Kalita, Nibedita, Spassov, Borislav, Semkov, Evgeni
In this work, we report the presence of rapid intra-night optical variations in both -- flux and polarization of the blazar BL Lacertae during its unprecedented 2020--2021 high state of brightness. The object showed significant flux variability and s
Externí odkaz:
http://arxiv.org/abs/2304.03975
The continuous monitoring capability of Fermi-LAT has enabled the exploration of Quasi-Periodic Oscillations (QPOs) in the $\gamma$-ray light curve of blazar that has given a new perspective to probe these sources over a wide range of time scales. We
Externí odkaz:
http://arxiv.org/abs/2211.00588