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ART2: coupling Lyα line and multi-wavelength continuum radiative transfer
- Source :
- Monthly Notices of the Royal Astronomical Society. 424:884-901
- Publication Year :
- 2012
- Publisher :
- Oxford University Press (OUP), 2012.
-
Abstract
- Narrow-band Lya line and broad-band continuum have played important roles in the discovery of high-redshift galaxies in recent years. Hence, it is crucial to study the radiative transfer of both Lya and continuum photons in the context of galaxy formation and evolution in order to understand the nature of distant galaxies. Here, we present a three-dimensional Monte Carlo radiative transfer code, All-wavelength Radiative Transfer with Adaptive Refinement Tree (ART^2), which couples Lya line and multi-wavelength continuum, for the study of panchromatic properties of galaxies and interstellar medium. This code is based on the original version of Li et al., and features three essential modules: continuum emission from X-ray to radio, Lya emission from both recombination and collisional excitation, and ionization of neutral hydrogen. The coupling of these three modules, together with an adaptive refinement grid, enables a self-consistent and accurate calculation of the Lya properties. As an example, we apply ART^2 to a cosmological simulation that includes both star formation and black hole growth, and study in detail a sample of massive galaxies at redshifts z=3.1 - 10.2. We find that these galaxies are Lya emitters (LAEs), whose Lya emission traces the dense gas region, and that their Lya lines show a shape characteristic of gas inflow. Furthermore, the Lya properties, including photon escape fraction, emergent luminosity, and equivalent width, change with time and environment. Our results suggest that LAEs evolve with redshift, and that early LAEs such as the most distant one detected at z ~ 8.6 may be dwarf galaxies with a high star formation rate fueled by infall of cold gas, and a low Lya escape fraction.
- Subjects :
- Physics
010308 nuclear & particles physics
Star formation
Astronomy and Astrophysics
Lyman-alpha line
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
01 natural sciences
Redshift
Galaxy
Space and Planetary Science
0103 physical sciences
Galaxy formation and evolution
Radiative transfer
010303 astronomy & astrophysics
Equivalent width
Astrophysics::Galaxy Astrophysics
Dwarf galaxy
Subjects
Details
- ISSN :
- 00358711
- Volume :
- 424
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Accession number :
- edsair.doi...........8162c9c1271329296c1e732f65875910