English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

The Beaming Pattern and Spectrum of Radiation from Inverse Compton Scattering in Blazars

MPS-Authors
/persons/resource/persons30507

Georganopoulos,  M.
Prof. Heinrich J. Völk, Emeriti, MPI for Nuclear Physics, Max Planck Society;

/persons/resource/persons30680

Kirk,  J.G.
Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Georganopoulos, M., Kirk, J., & Mastichiadis, A. (2001). The Beaming Pattern and Spectrum of Radiation from Inverse Compton Scattering in Blazars. The Astrophysical Journal, 561(1), 111-117.


Cite as: https://hdl.handle.net/11858/00-001M-0000-0011-8556-7
Abstract
By including Klein-Nishina effects, we generalize previous calculations of the beaming pattern of photons produced by inverse Compton scattering. For an isotropic distribution of soft photons upscattered by nonthermal electrons with a power-law density distribution n(γ)~γ-p, embedded in a plasma moving with relativistic bulk speed, we show that the observed radiation intensity is proportional to D3+p, where D is the Doppler boosting factor. This agrees with previous computations performed in the Thomson limit, where the observed spectral index is α=(p-1)/2 and the beaming pattern is D4+2α. Independent of D, Klein-Nishina effects limit the location of the peak energy &epsis;peakmec2 of the observed spectral energy distribution such that &epsis;peak<~1/&epsis;0, where &epsis;0 is the energy of the seed photons in units of mec2. Assuming that the seed photons originate in the broad-line region, we demonstrate that the GeV emission of blazars is significantly modified by Klein-Nishina effects, the spectrum being softer than that calculated in the Thomson limit. We further show that the change in the spectral index of the inverse Compton emission across &epsis;peak can exceed the value of 0.5 predicted by computations performed in the Thomson limit. The model spectra agree with OSSE and COMPTEL limits on this break without invoking the effects of differential absorption at the edge of a gamma-ray photosphere.