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Related papers: Broadband Spectral Fitting of Blazars using XSPEC

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We present a new time-dependent leptonic code that we developed to model the varying multi-wavelength (MWL) emission during blazar flares. In our modeling, we assume that the blazar emission originates from a plasma blob located in the jet,…

High Energy Astrophysical Phenomena · Physics 2020-03-18 A. Dmytriiev , H. Sol , A. Zech

Blazars, the jet dominated class of AGN comprising flat spectrum radio quasars (FSRQs) and BL Lac objects (BL Lacs) are now increasingly identified as potential sources of high energy neutrinos. Such neutrino blazars are ideal targets to…

High Energy Astrophysical Phenomena · Physics 2026-04-09 Athira M Bharathan , C. S. Stalin , Markus Böttcher , S. Sahayanathan , Blesson Mathew , Subir Bhattacharyya

Spectral Energy Distribution (SED) fitting is a well-developed astrophysical tool that has recently been applied to high-redshift Lyman Alpha-emitting galaxies. If rest-frame ultraviolet through near-infrared photometry is available, it…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Eric Gawiser

Blazars are a small fraction of all extragalactic sources but, unlike other objects, they are strong emitters across the entire electromagnetic spectrum. In this study we have conducted a detailed investigation of the broad-band spectral…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 S. Cutini , D. Gasparrini , P. Giommi , M. N. Mazziotta , C. Monte

In recent years, blazar surveys at radio and X-ray energies have greatly increased our understanding of this type of active galaxy. The combination of multi-wavelength data has shown that blazars follow a well defined sequence in terms of…

Astrophysics · Physics 2007-05-23 I. de la Calle Perez

Accurately measuring stellar parameters is a key goal to increase our understanding of the observable universe. However, current methods are limited by many factors, in particular, the biases and physical assumptions that are the basis for…

Solar and Stellar Astrophysics · Physics 2022-04-11 Jose I. Vines , James S. Jenkins

ROSAT observations of a large sample of bright gamma-ray (E > 100 MeV) blazars are presented. Results of a detailed spectral analysis in the soft $\sim$ 0.1-2.0 keV energy range are discussed in relation to the overall energy distribution…

Astrophysics · Physics 2016-08-30 A. Comastri , G. Fossati , G. Ghisellini , S. Molendi

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 C. J. Walcher , B. Groves , T. Budavari , D. Dale

Modeling the broadband emission of blazars has become increasingly challenging with the advent of multimessenger observations. Building upon previous successes in applying convolutional neural networks (CNNs) to leptonic emission scenarios,…

High Energy Astrophysical Phenomena · Physics 2025-07-01 N. Sahakyan , D. Bégué , A. Casotto , H. Dereli-Bégué , V. Vardanyan , M. Khachatryan , P. Giommi , A. Pe'er

We calculate the spectral energy distribution (SED) of electromagnetic radiation and the spectrum of high energy neutrinos from BL Lac objects in the context of the Synchrotron Proton Blazar Model. In this model, the high energy hump of the…

Astrophysics · Physics 2008-11-26 A. Muecke , R. J. Protheroe , R. Engel , J. P. Rachen , T. Stanev

The source CGRaBS~J0211$+$1051 (MG1 J021114+1051, z=0.20) flared up on 2011 January 23 in high-energy $\gamma$-rays as reported by {\it Fermi}/LAT. This event was followed by the increased activity at the UV, optical and radio frequencies…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Sunil Chandra , Kiran S Baliyan , Shashikiran Ganesh , Luigi Foschini

The phenomenology of gamma-ray bright blazars can be accounted for by a sequence in the source power and intensity of the diffuse radiation field surrounding the relativistic jet. Correspondingly, the equilibrium particle distribution peaks…

Astrophysics · Physics 2009-10-30 G. Ghisellini , A. Celotti , G. Fossati , L. Maraschi , A. Comastri

High synchrotron energy peaked blazar 1ES 1959+650 is studied with Swift and XMM-Newton satellite in total 127 observations during the period June 2018-December 2020. We extensively studied its flux and spectral variability on intra-day and…

High Energy Astrophysical Phenomena · Physics 2023-07-12 Kiran A Wani , Haritma Gaur , M K Patil

We present the results of blazar 3C 273 obtained from simultaneous observations obtained using XMM-Newton and NuSTAR satellites during the period 2015-2019 in five epochs. When the spectra are modeled with a power-law, significant residuals…

High Energy Astrophysical Phenomena · Physics 2025-02-19 Haritma Gaur , Main Pal , Muhammad S. Anjum , Kiran Wani , Pankaj Kushwaha , Ashwani Pandey , Liang Chen

Black hole X-ray binaries (BHBs) offer insights into extreme gravitational environments and the testing of general relativity. The X-ray spectrum collected by NICER offers valuable information on the properties and behaviour of BHBs through…

Instrumentation and Methods for Astrophysics · Physics 2024-04-03 Ethan Tregidga , James Steiner , Cecilia Garraffo , Carter Rhea , Mayeul Aubin

A detailed multi-epoch study of the broadband spectral behaviour of the very high energy (VHE) source, 1ES\,1011+496, provides us with valuable information regarding the underlying particle distribution. Simultaneous observations of the…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Atreyee Sinha , S. Sahayanathan , B. S. Acharya , G. C. Anupama , V. R. Chitnis , B. B. Singh

A method is developed for fitting theoretically predicted astronomical spectra to an observed spectrum. Using a hierarchical Bayesian principle, the method takes both systematic and statistical measurement errors into account, which has not…

Astrophysics · Physics 2008-11-26 Z. Shkedy , L. Decin , G. Molenberghs , C. Aerts

The jets of powerful blazars propagate within regions relatively dense of radiation produced externally to the jet. This radiation is a key ingredient to understand the origin of the high energy emission of blazars, from the X-ray to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 G. Ghisellini , F. Tavecchio

Electromagnetic radiation from blazar jets often displays strong variability, extending from radio to $\gamma$-ray frequencies. In a few cases, this variability has been characterized using Fourier time lags, such as those detected in the…

High Energy Astrophysical Phenomena · Physics 2016-06-29 Tiffany R. Lewis , Peter A. Becker , Justin D. Finke