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Title: Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit

Abstract

The shapes of relativistic iron lines observed in spectra of candidate black holes carry the signatures of the strong gravitational fields in which the accretion disks lie. These lines result from the sum of the contributions of all images of the disk created by gravitational lensing, with the direct and first-order images largely dominating the overall shapes. Higher order images created by photons tightly winding around the black holes are often neglected in the modeling of these lines, since they require a substantially higher computational effort. With the help of the strong deflection limit, we present the most accurate semi-analytical calculation of these higher order contributions to the iron lines for Schwarzschild black holes. We show that two regimes exist depending on the inclination of the disk with respect to the line of sight. Many useful analytical formulae can be also derived in this framework.

Authors:
;  [1]
  1. Dipartimento di Fisica 'E.R. Caianiello', Via Giovanni Paolo Secondo 132, Fisciano, SA, I-84084 Italy (Italy)
Publication Date:
OSTI Identifier:
22680022
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; BLACK HOLES; GRAVITATIONAL FIELDS; GRAVITATIONAL LENSES; INCLINATION; IRON; RELATIVISTIC RANGE; SCHWARZSCHILD METRIC; SIMULATION; SPECTRA

Citation Formats

Aldi, Giulio Francesco, and Bozza, Valerio, E-mail: giuliofrancesco.aldi@sa.infn.it, E-mail: valboz@sa.infn.it. Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/02/033.
Aldi, Giulio Francesco, & Bozza, Valerio, E-mail: giuliofrancesco.aldi@sa.infn.it, E-mail: valboz@sa.infn.it. Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit. United States. doi:10.1088/1475-7516/2017/02/033.
Aldi, Giulio Francesco, and Bozza, Valerio, E-mail: giuliofrancesco.aldi@sa.infn.it, E-mail: valboz@sa.infn.it. Wed . "Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit". United States. doi:10.1088/1475-7516/2017/02/033.
@article{osti_22680022,
title = {Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit},
author = {Aldi, Giulio Francesco and Bozza, Valerio, E-mail: giuliofrancesco.aldi@sa.infn.it, E-mail: valboz@sa.infn.it},
abstractNote = {The shapes of relativistic iron lines observed in spectra of candidate black holes carry the signatures of the strong gravitational fields in which the accretion disks lie. These lines result from the sum of the contributions of all images of the disk created by gravitational lensing, with the direct and first-order images largely dominating the overall shapes. Higher order images created by photons tightly winding around the black holes are often neglected in the modeling of these lines, since they require a substantially higher computational effort. With the help of the strong deflection limit, we present the most accurate semi-analytical calculation of these higher order contributions to the iron lines for Schwarzschild black holes. We show that two regimes exist depending on the inclination of the disk with respect to the line of sight. Many useful analytical formulae can be also derived in this framework.},
doi = {10.1088/1475-7516/2017/02/033},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 02,
volume = 2017,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}