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

Journal Article · · Astrophysical Journal

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.

OSTI ID:
22518784
Journal Information:
Astrophysical Journal, Vol. 812, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English