Results 121 to 130 of about 34,519 (239)

Constraining Extragalactic Background Light From TeV Blazars

, 2010
Our goal is to research the upper limits on the extragalactic background light (EBL). The upper limits on the extragalactic background light (EBL), using the Fermi and very high energy (VHE) spectra recently observed in TeV blazars, are presented. We use
Abdo, Abdo, Abdo, Acciari, Acciari, Acciari, Acciari, Acciari, Aharonian, Aharonian, Aharonian, Aharonian, Aharonian, Aharonian, Aharonian, Albert, Albert, Albert, Albert, Albert, Albert, Albert, Albert, Albert, Anderhub, Donea, Essey, Finke, Finke, Franceschini, Georganopoulos, Gilmore, Gould, Hauser, J. Wang, J. Yang, Kneiske, Kneiske, Madau, Malkan, Malkan, Mankuzhiyil, Mazin, Nilsson, Prandini, Razzaque, Salamon, Sbarufatti, Sbarufatti, Schroedter, Stanev, Stecker, Stecker, Stecker, Stecker, Stickel, Tagliaferri, Yang   +57 more
core   +1 more source

Jets, Blazars and the EBL in the GLAST-EXIST Era

, 2007
The synergy of GLAST and the proposed EXIST mission as the Black Hole Finder Probe in the Beyond Einstein Program is remarkable. With its full-sky per orbit hard X-ray imaging (3-600 keV) and "nuFnu" sensitivity comparable to GLAST, EXIST could measure ...
Grindlay, Jonathan E., Team, the EXIST
core   +1 more source

Exploring γ-Ray Flares from High-Redshift Blazar B3 1343+451 at GeV Energies

Universe
We study the temporal and spectral variability properties of the high-redshift blazar B3 1343+451 utilizing Fermi-LAT data from 2008 to 2022 in the energy range of 0.1–300 GeV.
Xiongfei Geng, Yang Liu, Gang Cao, Jing Fan, Xiongbang Yang, Nan Ding, Minghu Gao, Yehui Yang, Zhijie Zhang   +8 more
doaj   +1 more source

The physical properties of candidate neutrino-emitter blazars [PDF]

EPJ Web of Conferences
High-energy neutrinos detected by the IceCube Observatory provide a unique opportunity to study the origin of cosmic rays and the nature of the sources producing them.
Azzollini A., Buson S., Coleiro A., Fichet de Clairfontaine G., Pfeiffer L., Sanchez Zaballa J. M., Boughelilba M., Lincetto M.   +7 more
doaj   +1 more source

A method for setting upper limits to the extragalactic background light with Fermi-LAT and TeV observations of blazars

, 2010
We propose a method for setting upper limits to the extragalactic background light (EBL). Our method uses simultaneous {\em Fermi}-LAT and ground-based TeV observations of blazars and is based on the assumption that the intrinsic spectral energy ...
Abdo, Abdo, Acciari, Aharonian, Aharonian, Albert, Albert, Amelino-Camelia, Atoyan, Béthermin, Böttcher, Błażejowski, Dermer, Dwek, Fazio, Finke, Finke, Georganopoulos, Mannheim, Primack, Razzaque, Salamon, Schrödter, Stanev, Stecker, Stecker   +25 more
core   +1 more source

Sharp Polarimetric Eyes: More Trees than Forest?

Galaxies, 2016
The Fermi Gamma-ray Space Telescope (Fermi) has focused the intensive multi-wavelength and international observational effort on blazars since it was launched in 2008. Part of this effort involves systematic monitoring of the highly variable polarization
Paul S. Smith
doaj   +1 more source

Diagnosing Magnetic Field Geometry in Blazar Jets Using Multi-Frequency, Centimeter-Band Polarimetry and Radiative Transfer Modeling

Galaxies, 2020
We use multi-frequency linear polarization observations from the University of Michigan blazar program (UMRAO), in combination with radiative transfer simulations of emission from a relativistic jet, to investigate the time-dependent flow conditions ...
Margo Aller, Philip Hughes, Hugh Aller, Talvikki Hovatta   +3 more
doaj   +1 more source

Optical Outburst of the Blazar S4 0954+658 in Early 2015

Galaxies, 2016
We analyze the behavior of the BL Lac object S4 0954+658 during an unprecedented bright optical flare in early 2015. The optical flare was accompanied by a powerful γ -ray flare and the detection of very-high-energy γ -ray emission.
Daria Morozova, Valeri Larionov, Svetlana Jorstad, Alan Marscher, Yulia Troitskaya, Ivan Troitskiy, Dmitriy Blinov, Georg Borman, Mark Gurwell   +8 more
doaj   +1 more source

A 31.3 day Transient Quasiperiodic Oscillation in Gamma-ray Emission from Blazar S5 0716+714 [PDF]

, 2022
Junping Chen, Ting-Feng Yi, Yunlu Gong, Xing Yang, Zhihui Chen, Xin Chang, Lisheng Mao   +6 more
openalex   +1 more source

Long-Term Multi-Band and Polarimetric View of Mkn 421: Motivations for an Integrated Open-Data Platform for Blazar Optical Polarimetry

Galaxies, 2017
In this work, by making use of the large software and database resources made available through online facilities such as the ASI Science Data Center (ASDC), we present a novel approach to the modelling of blazar emission whereby the multi-epoch SED for ...
Ulisses Barres de Almeida, Bernardo M. O. Fraga, Paolo Giommi, Narek Sahakyan, Sargis Gasparyan, Carlos H. Brandt   +5 more
doaj   +1 more source