Seed photon fields of blazars in the internal shock scenario

Journal Article · Sun Apr 20 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/785/2/132· OSTI ID:22357089

Joshi, M.; Marscher, A. P. ^[1]; Böttcher, M. ^[2]

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1. Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)
2. Centre for Space Research, North-West University, Potchefstroom Campus, Potchefstroom 2520 (South Africa)

We extend our approach of modeling spectral energy distribution (SED) and light curves of blazars to include external Compton (EC) emission due to inverse Compton scattering of an external anisotropic target radiation field. We describe the time-dependent impact of such seed photon fields on the evolution of multifrequency emission and spectral variability of blazars using a multi-zone time-dependent leptonic jet model, with radiation feedback, in the internal shock model scenario. We calculate accurate EC-scattered high-energy (HE) spectra produced by relativistic electrons throughout the Thomson and Klein-Nishina regimes. We explore the effects of varying the contribution of (1) a thermal Shakura-Sunyaev accretion disk, (2) a spherically symmetric shell of broad-line clouds, the broad-line region (BLR), and (3) a hot infrared emitting dusty torus (DT), on the resultant seed photon fields. We let the system evolve to beyond the BLR and within the DT and study the manifestation of the varying target photon fields on the simulated SED and light curves of a typical blazar. The calculations of broadband spectra include effects of γ-γ absorption as γ-rays propagate through the photon pool present inside the jet due to synchrotron and inverse Compton processes, but neglect γ-γ absorption by the BLR and DT photon fields outside the jet. Thus, our account of γ-γ absorption is a lower limit to this effect. Here, we focus on studying the impact of parameters relevant for EC processes on HE emission of blazars.

• OSTI ID: 22357089
• Journal Information: Astrophysical Journal, Vol. 785, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
ACCRETION DISKS
ANISOTROPY
BL LACERTAE OBJECTS
COMPTON EFFECT
EMISSION
ENERGY SPECTRA
FEEDBACK
GALAXIES
HYDRODYNAMICS
JET MODEL
LET
PHOTONS
RADIANT HEAT TRANSFER
RELATIVISTIC RANGE
SIMULATION
SPHERICAL CONFIGURATION
SYMMETRY
TIME DEPENDENCE
VISIBLE RADIATION