English
Related papers

Related papers: Constraining X-ray variability of the blazar 3C 27…

200 papers

We present X-ray intraday variability and power spectral density (PSD) analyses of the longest 23 pointed XMM-Newton observations of the blazar 3C 273 that were taken during 2000 -- 2021. These good time intervals contained between 5 and…

High Energy Astrophysical Phenomena · Physics 2022-02-23 G. S. Pavana Gowtami , Haritma Gaur , Alok C. Gupta , Paul J. Wiita , Mai Liao , Martin Ward

We have undertaken a nearly simultaneous optical/UV and X-ray variability study of the flat spectrum radio quasar, 3C 273 using data available from the XMM$-$Newton satellite mission from June 2000 to July 2012. Here we focus on the…

Astrophysics of Galaxies · Physics 2015-06-02 Nibedita Kalita , Alok C. Gupta , Paul J. Wiita , Jai Bhagwan , Kalpana Duorah

The X-ray emission from blazars has been widely investigated using several space telescopes. In this work, we explored statistical properties of the X-ray variability in the blazars S5 0716+714, OJ 287, Mkn 501 and RBS 2070 using the…

We present an update of 3C 273's database hosted by the ISDC, completed with data from radio to gamma-ray observations over the last 10 years. We use this large data set to study the multiwavelength properties of this quasar,especially…

Blazars, a class of active galactic nuclei (AGN) powered by supermassive black holes, are known for their remarkable variability across multiple timescales and wavelengths. Despite significant advancements in our understanding of AGN…

High Energy Astrophysical Phenomena · Physics 2025-02-04 Gopal Bhatta , Suvas C. Chaudhary , Niraj Dhital , Tek P. Adhikari , Maksym Mohorian , Radim Pánis , Raghav Neupane , Yogesh Singh Maharjan

Detailed investigation of broadband flux variability in the blazar 3C 273 allows us to probe the location and size of emission regions and their physical conditions. We report the results on correlation studies of the flaring activity…

We present X-ray intraday variability, cross-correlated variability, and power spectrum density analysis of the binary black hole blazar candidate OJ 287. The X-ray pointed observations of the source were carried out on eight occasions by…

High Energy Astrophysical Phenomena · Physics 2026-03-09 Tao Huang , Alok C. Gupta , Lang Cui , Ashutosh Tripathi , Yongfeng Huang , P. U. Devanand , Xiang Liu

We present the results of a long-look monitoring of 3C273 with RXTE between 1996 and 2000. A total of 230 observations amounts to a net exposure of 845ksec, with this spectral and variability analysis of 3C273 covering the longest…

We present and analyse the WEBT multifrequency observations of 3C 454.3 in the 2007-2008 observing season, including XMM-Newton observations and near-IR spectroscopic monitoring, and compare the recent emission behaviour with the past one.…

Astrophysics · Physics 2009-11-13 C. M. Raiteri , M. Villata , V. M. Larionov , M. A. Gurwell , W. P. Chen

We present the results of timing and spectral analysis of the blazar H 2356-309 using XMM-Newton observations. This blazar is observed during 13 June 2005-24 December 2013 in total nine observations. Five of the observations show moderate…

High Energy Astrophysical Phenomena · Physics 2020-09-07 Kiran A. Wani , Haritma Gaur

We present a study of the flux distribution of a sample of 15 Intermediate and Low-energy peaked blazars using XMM-Newton observations in a total of 57 epochs on short-term timescales. We characterise the X-ray variability of all of the…

High Energy Astrophysical Phenomena · Physics 2022-11-07 Kiran Wani , Haritma Gaur

Context. Investigation of the hard X-ray emission properties of blazars is key to the understanding of the central engine of the sources and associated jet process. In particular, simultaneous spectral and timing analyses of the intra-day…

High Energy Astrophysical Phenomena · Physics 2018-11-14 Gopal Bhatta , Maksym Mohorian , Illya Bilinsky

Here we report our recent results of variability studies in optical and X-ray bands of three blazars namely 3C 273, PKS 2155 - 304 and BL Lacertae with XMM-Newton. We found large amplitude optical to X-rays variability in 3C 273, and PKS…

High Energy Astrophysical Phenomena · Physics 2017-12-20 A. C. Gupta

We analyze X-ray light curves of the blazars Mrk 421, PKS 2155-304, and 3C 273 using observations by the Soft X-ray Telescope on board AstroSat and archival XMM-Newton data. We use light curves of length 30-90 ks each from 3-4 epochs for…

High Energy Astrophysical Phenomena · Physics 2023-10-27 Joy Bhattacharyya , Ritesh Ghosh , Ritaban Chatterjee , Nabanita Das

Characterisation of the long-term variations in the broad line region in a luminous blazar, where Comptonisation of broad-line emission within a relativistic jet is the standard scenario for production of gamma-ray emission that dominates…

High Energy Astrophysical Phenomena · Physics 2020-08-04 Krzysztof Nalewajko , Alok C. Gupta , Mai Liao , Krzysztof Hryniewicz , Maitrayee Gupta , Minfeng Gu

Due to its peculiar and highly variable nature, the blazar 3C 454.3 has been extensively monitored by the WEBT team. Here, we present for the first time these long-term optical flux and color variability results using data acquired in B, V,…

At the end of March 2004, the blazar S5 0716+714 underwent an optical outburst that prompted for quasi-simultaneous target-of-opportunity observations with the INTEGRAL and XMM-Newton satellites. In this paper, we report the results of the…

We present multiwavelength light curves and polarimetric data of the Flat Spectrum Radio Quasar 3C 273 over 8 years. The wavelength range of our data set extends from radio to gamma-rays. We found that the optical emission in this source is…

High Energy Astrophysical Phenomena · Physics 2020-07-22 Sunil Fernandes , Víctor M. Patiño-Álvarez , Vahram Chavushyan , Eric M. Schlegel , José Ramón Valdés

The aim of this paper is to study the evolution of the broadband spectrum of one of the brightest and nearest quasars 3C 273. We analyze the data obtained during quasi-simultaneous INTEGRAL and XMM monitoring of the blazar 3C 273 in…

The bright blazar Mkn 421 has been observed four times for uninterrupted durations of ~ 9 - 13 hr during the performance verification and calibration phases of the XMM-Newton mission. The source was strongly variable in all epochs, with…

Astrophysics · Physics 2009-11-07 S. Sembay , R. Edelson , A. Markowitz , R. G. Griffiths , M. J. L. Turner
‹ Prev 1 2 3 10 Next ›