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Title: A SYSTEMATIC STUDY OF Lyα TRANSFER THROUGH OUTFLOWING SHELLS: MODEL PARAMETER ESTIMATION

Outflows promote the escape of Lyman-α (Lyα) photons from dusty interstellar media. The process of radiative transfer through interstellar outflows is often modeled by a spherically symmetric, geometrically thin shell of neutral gas that scatters photons emitted by a central Lyα source. Despite its simplified geometry, this “shell model” has been surprisingly successful at reproducing observed Lyα line shapes. In this paper, we perform automated line fitting on a set of noisy simulated shell-model spectra in order to determine whether degeneracies exist between the different shell-model parameters. While there are some significant degeneracies, we find that most parameters are accurately recovered, especially the H i column density (N{sub H} {sub i}) and outflow velocity (v{sub exp}). This work represents an important first step in determining how the shell-model parameters relate to the actual physical properties of Lyα sources. To aid further exploration of the parameter space, we have made our simulated model spectra available through an interactive online tool.
Authors:
; ;  [1]
  1. Institute of Theoretical Astrophysics, University of Oslo, Postboks 1029 Blindern, NO-0315 Oslo (Norway)
Publication Date:
OSTI Identifier:
22518784
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 812; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DENSITY; GALAXIES; HYDROGEN; INTERSTELLAR SPACE; LYMAN LINES; RADIANT HEAT TRANSFER; RED SHIFT; SCATTERING; SPACE; SYMMETRY; VELOCITY