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Full-Text Articles in Physical Sciences and Mathematics
Spectral Energy Distribution Of Markarian 501: Quiescent State Versus Extreme Outburst, P. T. Reynolds, Veritas, Magic
Spectral Energy Distribution Of Markarian 501: Quiescent State Versus Extreme Outburst, P. T. Reynolds, Veritas, Magic
Physical Sciences Publications
The very high energy (VHE; E > 100 GeV) blazar Markarian 501 (Mrk 501) has a well-studied history of extreme spectral variability and is an excellent laboratory for studying the physical processes within the jets of active galactic nuclei. However, there are few detailed multiwavelength studies of Mrk 501 during its quiescent state, due to its low luminosity. A short-term multiwavelength study of Mrk 501 was coordinated in 2009 March, focusing around a multi-day observation with the Suzaku X-ray satellite and including γ-ray data from VERITAS, MAGIC, and the Fermi Gamma-ray Space Telescope with the goal of providing a well-sampled multiwavelength …
Insights Into The High-Energy Gamma-Ray Emission Of Markarian 501 From Extensive Multifrequency Observations In The Fermi Era, P. T. Reynolds, Fermi-Lat, Magic, Veritas
Insights Into The High-Energy Gamma-Ray Emission Of Markarian 501 From Extensive Multifrequency Observations In The Fermi Era, P. T. Reynolds, Fermi-Lat, Magic, Veritas
Physical Sciences Publications
We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do …
Multi-Wavelength Observations Of The Flaring Gamma-Ray Blazar 3c 66a In 2008 October, P. T. Reynolds, Fermi-Lat, Veritas, Gasp-Webt
Multi-Wavelength Observations Of The Flaring Gamma-Ray Blazar 3c 66a In 2008 October, P. T. Reynolds, Fermi-Lat, Veritas, Gasp-Webt
Physical Sciences Publications
The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with an external …