Radiation Processes

Böttcher, M.; Reimer, A.

doi:10.1002/9783527641741.ch3

Cited by 9 publications

(4 citation statements)

References 43 publications

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“…The magnetic field strength in the emitting region can be estimated with the following line of argument (Rybicki & Lightman 2007;Böttcher 2012). The synchrotron cooling time of a particle radiating at 86 GHz is given by Larmor's formula for relativistic particles.…”

Section: Estimating the Magnetic Field Inside The 86 Ghz And 22 Ghz C...mentioning

confidence: 99%

A highly magnetized twin-jet base pinpoints a supermassive black hole

Baczko

Schulz

Kadler

et al. 2016

A&A

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Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical models based on (Blandford & Znajek 1977, MNRAS, 179, 433) extract the rotational energy from a Kerr black hole, which could be the case for NGC 1052, to launch these jets. This requires magnetic fields on the order of 10 3 G to 10 4 G. We imaged the vicinity of the SMBH of the AGN NGC 1052 with the Global Millimetre VLBI Array and found a bright and compact central feature that is smaller than 1.9 light days (100 Schwarzschild radii) in radius. Interpreting this as a blend of the unresolved jet bases, we derive the magnetic field at 1 Schwarzschild radius to lie between 200 G and ∼8.3 × 10 4 G consistent with Blandford & Znajek models.

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Section: Estimating the Magnetic Field Inside The 86 Ghz And 22 Ghz C...mentioning

confidence: 99%

A highly magnetized twin-jet base pinpoints a supermassive black hole

Baczko

Schulz

Kadler

et al. 2016

A&A

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“…Then for 10 random points between two successive Compton scatterings, we determine the position and direction of motion of the particles at these points and write the spectral power in synchrotron radiation P ν into a synchrotron output file for the angular bin corresponding to the electron's/positron's direction of motion. The synchrotron power P ν of a single e ± is approximated as: (Böttcher & Reimer 2012) where the critical frequency ν c = 3qB 4πmec γ 2 sin ψ = 4.2 × 10 6 sin ψB G γ 2 Hz with B G being the magnetic field in units of Gauss. The approximation (1) represents the synchrotron spectrum to whithin a few % at all frequencies.…”

Section: Model Setup and Code Descriptionmentioning

confidence: 99%

“…(1) (Böttcher & Reimer 2012) where the critical frequency ν c = 3qB 4πmec γ 2 sin ψ = 4.2 × 10 6 sin ψB G γ 2 Hz with B G being the magnetic field in units of Gauss. The approximation (1) represents the synchrotron spectrum to whithin a few % at all frequencies.…”

Section: Model Setup and Code Descriptionmentioning

confidence: 99%

Time-Dependence of VHE gamma-ray induced Pair Cascades in AGN Environments

Roustazadeh¹

2016

Proceedings of 3rd Annual Conference on High Energy Astrophysics in Southern Africa — PoS(HEASA2015)

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The discovery of very-high-energy (VHE, E > 100 GeV) γ-ray emission from intermediate-and low-frequency peaked blazars suggests that γγ absorption and pair cascading might occur in those objects. In previous papers, we investigated the Compton emission from VHE γ-ray induced pair cascades, deflected by moderate magnetic fields, in a largely model-independent way, and demonstrated that this emission can explain the Fermi fluxes and spectra of the radio galaxies Cen A and NGC 1275. In this paper, we describe a generalization of our Monte-Carlo cascade code to include the angle-dependent synchrotron output from the cascades, allowing for the application to situations with non-negligible magnetic fields, leading to potentially observable synchrotron signatures, but still not dominating the radiative energy loss of cascade particles. We confirm that the synchrotron radiation from the cascades in NGC 1275 and Cen A are negligible for the parameters used in our previous works. We demonstrate that the magnetic field can not be determined from a fit of the cascade emission to the γ-ray spectrum alone, and the degeneracy can only be lifted if the synchrotron emission from the cascades is observed as well. We illustrate this fact with the example of NGC 1275. We point out that the cascade synchrotron emission may produce spectral features in the same energy range in which the big blue bump is observed in the spectral energy distributions of several blazars, and may make a non-negligible contribution to this feature. We illustrate this idea with the example of 3C 279.

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“…The following sub-sections provide a brief overview of the main radiation physics aspects of both leptonic and hadronic models. A more in-depth review of the radiation physics in relativistic jets can be found in [33].…”

Section: Leptonic and Hadronic Blazar Modelsmentioning

confidence: 99%

Modeling the Spectral Energy Distributions and Variability of Blazars

Boettcher

2012

Preprint

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Radiation Processes

Cited by 9 publications

References 43 publications

A highly magnetized twin-jet base pinpoints a supermassive black hole

A highly magnetized twin-jet base pinpoints a supermassive black hole

Time-Dependence of VHE gamma-ray induced Pair Cascades in AGN Environments

Modeling the Spectral Energy Distributions and Variability of Blazars

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