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This study examines the flux and photon index distributions of 11 Very High Energy (VHE) Flat Spectrum Radio Quasars (FSRQs) using over 16 years of Fermi-LAT $\gamma$-ray data. The distributions reveal double lognormal profiles in both flux…

We present the results of the $\gamma$-ray flux distribution study on the brightest blazars which are observed by the \emph{Fermi}-LAT. We selected 50 brightest blazars based on the maximum number of detection reported in the LAT third AGN…

High Energy Astrophysical Phenomena · Physics 2018-11-07 Zahir Shah , N. Mankuzhiyil , A. Sinha , R. Misra , S. Sahayanathan , N. Iqbal

We present a determination of the distributions of gamma-ray photon flux -- the so called LogN-LogS relation -- and photon spectral index for blazars, based on the third extragalactic source catalog of the Fermi Gamma-ray Space Telescope's…

High Energy Astrophysical Phenomena · Physics 2015-10-07 J. Singal

We present a determination of the distributions of photon spectral index and gamma-ray flux - the so called LogN-LogS relation - for the 352 blazars detected with a greater than approximately seven sigma detection threshold and located…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 J. Singal , V. Petrosian , M. Ajello

Fermi-LAT LCR provide continuous and regularly-sampled gamma-ray light curves, spanning about 14 years, for a large sample of blazars. The log-normal flux distribution and linear RMS-Flux relation of the light curves for a few of Fermi…

High Energy Astrophysical Phenomena · Physics 2023-07-21 Na Wang , Ting-Feng Yi , Liang Wang , Li-Sheng Mao , Zhi-Yuan Pu , Gong-Ming Ning , Wei-Tian Huang , He Lu , Shun Zhang , Yu-Tong Chen , Liang Dong

The observed log-normal flux distributions in the high energy emission from blazars have been interpreted as being due to variability stemming from non-linear multiplicative processes generated dynamically from the accretion disc. On the…

High Energy Astrophysical Phenomena · Physics 2018-07-26 Atreyee Sinha , Rukaiya Khatoon , Ranjeev Misra , Sunder Sahayanathan , Soma Mandal , Rupjyoti Gogoi , Nilay Bhatt

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

We utilized a sample from the Fermi-LAT 14-year Source Catalog by adjusting the flux detection threshold, enabling us to derive the intrinsic source count distribution $dN/dF_{25}$ of extragalactic blazars using nonparametric, unbinned…

High Energy Astrophysical Phenomena · Physics 2024-08-28 Xuhang Yin , Houdun Zeng

We present results of variability study of a sample of 20 powerful blazars using Fermi/LAT (0.1--300 GeV) observations. We studied decade-long observations applying various analysis tools such as flux distribution, symmetry analysis, and…

High Energy Astrophysical Phenomena · Physics 2021-07-27 Gopal Bhatta , Niraj Dhital

We present a statistical characterization of the $\gamma$-ray emission from the four \emph{Fermi}-LAT sources: FR I radio galaxy NGC 1275, BL Lac Mrk 421, FSRQs B2 1520+31 and PKS 1510-089 detected almost continuously over a time…

High Energy Astrophysical Phenomena · Physics 2017-11-09 Pankaj Kushwaha , Atreyee Sinha , Ranjeev Misra , K. P. Singh , E. M. de Gouveia Dal Pino

Flux distribution is an important tool to understand the variability processes in active galactic nuclei. We now have available a great deal of observational evidences pointing towards the presence of log-normal components in the high…

High Energy Astrophysical Phenomena · Physics 2018-12-18 Carlo Romoli , Nachiketa Chakraborty , Daniela Dorner , Andrew M. Taylor , Michael Blank

We present a systematic characterization of multi-wavelength emission from blazar PKS 1510-089 using well-sampled data at infrared(IR)-optical, X-ray and $\gamma$-ray energies. The resulting flux distributions, except at X-rays, show two…

High Energy Astrophysical Phenomena · Physics 2016-04-29 Pankaj Kushwaha , Sunil Chandra , Ranjeev Misra , S. Sahayanathan , K. P. Singh , K. S. Baliyan

We report the results of optical monitoring for a sample of 11 blazars including 10 BL Lacs and 1 Flat Spectrum Radio Quasar (FSRQ). We have measured the multiband optical flux and colour variations in these blazars on intra-day and…

High Energy Astrophysical Phenomena · Physics 2013-11-21 Haritma Gaur , Alok C. Gupta , A. Strigachev , R. Bachev , E. Semkov , Paul J. Wiita , S. Peneva , S. Boeva , L. Slavcheva-Mihova , B. Mihov , G. Latev , U. S. Pandey

Determining whether the flux distribution of an Astrophysical source is a Gaussian or a log-normal, provides key insight into the nature of its variability. For lightcurves of moderate length ($< 10^3$), a useful first analysis is to test…

High Energy Astrophysical Phenomena · Physics 2020-07-01 Zahir Shah , Ranjeev Misra , Atreyee Sinha

We present the observational results of multi-colour optical monitoring of eight red blazars from 2003 September to 2004 February. The aim of our monitoring is to investigate the spectral variability as well as the flux variations at short…

Astrophysics · Physics 2009-11-11 Minfeng Gu , C. -U. Lee , Soojong Pak , H. S. Yim , A. B. Fletcher

The X-ray, Ultraviolet, Optical emission from radio-quiet AGNs, black hole binaries, and other compact sources, in general, follow a lognormal flux distribution, a linear rms-flux relation, and a (broken) power-law power spectral densities…

High Energy Astrophysical Phenomena · Physics 2020-03-04 Pankaj Kushwaha , Atreyee Sinha , Ranjeev Misra , K. P. Singh , E. M. de Gouveia Dal Pino

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

We present a detailed temporal and spectral analysis of the blazar S5\,1044+71 using multi-wavelength data obtained from the \emph{Fermi}-LAT and Swift-XRT/UVOT telescopes. Applying the Bayesian block algorithm to the 3-day binned…

High Energy Astrophysical Phenomena · Physics 2026-01-22 Sajad Ahanger , Shah Zahir , Sunder Sahayanathan , Naseer Iqbal , Zahoor Malik , Aaqib Manzoor

The time evolution of the electromagnetic emission from blazars, in particular high frequency peaked sources (HBLs), displays irregular activity not yet understood. In this work we report a methodology capable of characterizing the time…

High Energy Astrophysical Phenomena · Physics 2010-11-02 E. Resconi , D. Franco , A. Gross , L. Costamante , E. Flaccomio

We conducted a comprehensive temporal and spectral study of the FSRQ PKS 0805-07 by using the broadband observations from the Fermi-LAT and Swift-XRT/UVOT instruments over the period MJD 54684-60264. The 3-day binned $\gamma$-ray light…

High Energy Astrophysical Phenomena · Physics 2024-12-13 Sikandar A. Dar , Zahir Shah , Ranjeev Misra , Naseer Iqbal
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