2006/11/06 by Philippe Laurent, L. Titarchuk, Lev Titarchuk · 1 citation
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Atomic physics #Computational physics #Emission spectrum #Line (geometry) #Monte Carlo method #Optical depth #Optics #Outflow #Photon #Physics #Pulsars and Gravitational Waves Research #Recoil #Redshift #Spectral line #astro-ph
paper · pdf · doi:10.1086/510572
published as Astrophys.J.656:1056-1074,2007 · Accepted for publication in the Astrophysical Journal and it is scheduled for ApJ February 20, 2007, v 656, 2 issue
arxiv created 2006/11/06 · openalex publication_date 2007/02/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In an earlier paper, the general formulation and results for photon reprocessing (downscattering) that included recoil and Comptonization effects due to divergence of the flow were presented. In a second paper we showed the Monte Carlo (MC) simulated continuum and line spectra. We also provided an analytical description of the simulated continuum spectra using the diffusion approximation. We have simulated the propagation of monochromatic and continuum photons in a bulk outflow from a compact object. Electron scattering of the photons within the expanding flow leads to a decrease of their energy, which is of first order in V / c (where V is the outflow velocity). The downscattering effect of first order in V / c in the diverging flow is explained by semianalytical calculations and confirmed by MC simulations. We conclude that redshifted lines and downscattering bumps are intrinsic properties of the powerful outflows for which the Thomson optical depth is greater than 1. We fitted our model line profiles to the observations using four free parameters, β = V / c , the optical depth of the wind τ, the wind temperature kT e , and the original line photon energy E 0 . We show how the primary spectrum emitted close to the black hole is modified by reprocessing in the warm wind. In the framework of our wind model, the fluorescent iron line Kα is formed in the partly ionized wind as a result of illumination by central source continuum photons. The demonstrated application of our outflow model to the XMM-Newton observations of MCG -6-30-15 and to the ASCA observations of GRO J1655-40 points out a potential powerful spectral diagnostic for probes of the outflow-central object connection in Galactic and extragalactic black hole sources.