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J/A+A/531/A12       Grid of Lya radiation transfer models    (Schaerer+, 2011)

Grid of Lyα radiation transfer models for interpreting distant galaxies. Schaerer D., Hayes M., Verhamme A., Teyssier R. <Astron. Astrophys. 531, A12 (2011)> =2011A&A...531A..12S
ADC_Keywords: Models ; Interstellar medium ; Ultraviolet Keywords: galaxies: starburst - galaxies: ISM - galaxies: high-redshift - ultraviolet: galaxies - radiative transfer Abstract: Lyα is a key diagnostic for numerous observations of distant star-forming galaxies, but detailed radiation transfer models are required for interpreting them. We provide an extensive grid of 3D radiation transfer models that simulate the Lyα and UV continuum radiation transfer in the interstellar medium of star-forming galaxies. We have improved our Monte Carlo MCLya code and used it to compute a grid of 6240 radiation transfer models for homogeneous spherical shells containing HI and dust surrounding a central source. The simulations cover a wide range of parameter space. We present the detailed predictions from our models including in particular the Lyα escape fraction fesc, the continuum attenuation, and detailed Lyα line profiles. The Lyα escape fraction is shown to depend strongly on dust content, but also on other parameters (HI column density and radial velocity). The predicted line profiles show a wide diversity of morphologies, ranging from broad absorption lines to emission lines with complex features. The results from our simulations are distributed in electronic format. Our models should be of use for interpreting observations from distant galaxies, for other simulations, and should also serve as an important basis for comparison for future, more refined, radiation transfer models. Description: Derived quantities fesc (Lyα escape fraction), fesccont (escape fraction of continuum radiation close to Lyα), and Lyα equivalent width for a constant input spectrum (flat continuum) as a function of the 4 model parameters vexp (expansion velocity), NHI (HI column density), b (HI velocity dispersion), tau_a (dust absorption optical depth). The derived quantities have been computed for all 6240 models described by the model parameters and for different FWHM values of the input Lyα line. Note that the derived quantities are identical for cases of spherical infall with the same absolute radial velocity (|vexp|). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 58 68596 Predicted Lyα and continuum escape fraction for all radiation transfer models
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 6 F6.2 km/s b [10/160] HI velocity dispersion in the shell 8- 11 F4.2 --- tau.a [0/4] Dust absorption optical depth 13- 17 F5.2 [cm-2] log(NHI) [16/21.7] logarithm (dec.) of HI column density 19- 24 F6.2 km/s Vexp [0/700] Expansion velocity 26- 32 F7.2 km/s FWHM [50/1000] Full width at half maximum of input Lyα emission line 34- 40 F7.5 --- Fesc [0/1] Lyα escape fraction 42- 48 F7.5 --- Fesc-c [0/1] UV continuum escape fraction close to Lyα 50- 58 F9.5 0.1nm W(Lya) Lyα absorption equivalent width predicted for a flat UV continuum

(End) Daniel Schaerer [Geneva Obs., CH], Patricia Vannier [CDS] 05-May-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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