Abstract
view Abstract Citations (10) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Multizone Model for Composite Disk-Corona Structure and Spectral Formation in Active Galactic Nuclei Shimura, Toshiya ; Mineshige, Shin ; Takahara, Fumio Abstract We study a composite disk-corona structure in active galactic nuclei by solving for radiative transfer, hydrostatic balance, and energy balance at each layer with a different vertical height. A key assumption is that a fraction f of total energy is dissipated in a corona with a Thomson optical depth of τ_C_, and a remaining fraction, 1 - f within a main body of the disk. As f increases, a two-phased structure grows with an abrupt temperature jump at the interface. As a result, the emergent spectrum varies from a blackbody-like spectrum to a power-law spectrum with a high-energy cutoff. The power-law index is insensitive to a mass of a central black hole, accretion rate, and τ_C_ and decreases with an increase of f reaching ~0.9 for f ~ 1. The cutoff energy (E_cutoff_) is, on the other hand, related to τ_C_ as τ_C_ E_cutoff_ ~ 90 keV. The radiation field is a blackbody at the midplane of the disk, but has a power-law energy distribution near the surface due to a reflection of high-energy photons emanating from the corona. The resultant spectra thus produce litle UV bumps. To account for the observed AGN spectra, therefore, we should consider more complicated situations such as a partial coverage of hot corona and an effect of absorption by heavy elements. Publication: The Astrophysical Journal Pub Date: January 1995 DOI: 10.1086/175152 Bibcode: 1995ApJ...439...74S Keywords: Accretion Disks; Active Galactic Nuclei; Energy Budgets; Galactic Structure; Hydrostatics; Radiative Transfer; Ultraviolet Spectra; Equations Of State; Equilibrium Equations; Mathematical Models; Power Spectra; Temperature Profiles; Astrophysics; ACCRETION; ACCRETION DISKS; GALAXIES: NUCLEI; RADIATION MECHANISMS: THERMAL full text sources ADS |
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
