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Title: RADIATIVE TRANSFER MODELING OF Ly{alpha} EMITTERS. I. STATISTICS OF SPECTRA AND LUMINOSITY

Abstract

We combine a cosmological reionization simulation with box size of 100 h {sup -1} Mpc on a side and a Monte Carlo Ly{alpha} radiative transfer code to model Ly{alpha} Emitters (LAEs) at z {approx} 5.7. The model introduces Ly{alpha} radiative transfer as the single factor for transforming the intrinsic Ly{alpha} emission properties into the observed ones. Spatial diffusion of Ly{alpha} photons from radiative transfer results in extended Ly{alpha} emission and only the central part with high surface brightness can be observed. Because of radiative transfer, the appearance of LAEs depends on density and velocity structures in circumgalactic and intergalactic media as well as the viewing angle, which leads to a broad distribution of apparent (observed) Ly{alpha} luminosity for a given intrinsic Ly{alpha} luminosity. Radiative transfer also causes frequency diffusion of Ly{alpha} photons. The resultant Ly{alpha} line is asymmetric with a red tail. The peak of the Ly{alpha} line shifts toward longer wavelength and the shift is anti-correlated with the apparent-to-intrinsic Ly{alpha} luminosity ratio. The simple radiative transfer model provides a new framework for studying LAEs. It is able to explain an array of observed properties of z {approx} 5.7 LAEs in Ouchi et al., producing Ly{alpha} spectra, morphology, and apparentmore » Ly{alpha} luminosity function (LF) similar to those seen in observation. The broad distribution of apparent Ly{alpha} luminosity at fixed UV luminosity provides a natural explanation for the observed UV LF, especially the turnover toward the low luminosity end. The model also reproduces the observed distribution of Ly{alpha} equivalent width (EW) and explains the deficit of UV bright, high EW sources. Because of the broad distribution of the apparent-to-intrinsic Ly{alpha} luminosity ratio, the model predicts effective duty cycles and Ly{alpha} escape fractions for LAEs.« less

Authors:
 [1];  [2];  [3];  [4]
  1. Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06520 (United States)
  2. Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)
  3. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
  4. Institucio Catalana de Recerca i Estudis Avancats, Barcelona (Spain)
Publication Date:
OSTI Identifier:
21451133
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 716; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/716/1/574; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; BRIGHTNESS; COSMOLOGY; GALAXIES; LUMINOSITY; MONTE CARLO METHOD; MORPHOLOGY; PHOTONS; RED SHIFT; SCATTERING; SIMULATION; UNIVERSE; BOSONS; CALCULATION METHODS; ELEMENTARY PARTICLES; MASSLESS PARTICLES; OPTICAL PROPERTIES; PHYSICAL PROPERTIES

Citation Formats

Zheng, Zheng, Renyue, Cen, Trac, Hy, and Miralda-Escude, Jordi. RADIATIVE TRANSFER MODELING OF Ly{alpha} EMITTERS. I. STATISTICS OF SPECTRA AND LUMINOSITY. United States: N. p., 2010. Web. doi:10.1088/0004-637X/716/1/574.
Zheng, Zheng, Renyue, Cen, Trac, Hy, & Miralda-Escude, Jordi. RADIATIVE TRANSFER MODELING OF Ly{alpha} EMITTERS. I. STATISTICS OF SPECTRA AND LUMINOSITY. United States. https://doi.org/10.1088/0004-637X/716/1/574
Zheng, Zheng, Renyue, Cen, Trac, Hy, and Miralda-Escude, Jordi. 2010. "RADIATIVE TRANSFER MODELING OF Ly{alpha} EMITTERS. I. STATISTICS OF SPECTRA AND LUMINOSITY". United States. https://doi.org/10.1088/0004-637X/716/1/574.
@article{osti_21451133,
title = {RADIATIVE TRANSFER MODELING OF Ly{alpha} EMITTERS. I. STATISTICS OF SPECTRA AND LUMINOSITY},
author = {Zheng, Zheng and Renyue, Cen and Trac, Hy and Miralda-Escude, Jordi},
abstractNote = {We combine a cosmological reionization simulation with box size of 100 h {sup -1} Mpc on a side and a Monte Carlo Ly{alpha} radiative transfer code to model Ly{alpha} Emitters (LAEs) at z {approx} 5.7. The model introduces Ly{alpha} radiative transfer as the single factor for transforming the intrinsic Ly{alpha} emission properties into the observed ones. Spatial diffusion of Ly{alpha} photons from radiative transfer results in extended Ly{alpha} emission and only the central part with high surface brightness can be observed. Because of radiative transfer, the appearance of LAEs depends on density and velocity structures in circumgalactic and intergalactic media as well as the viewing angle, which leads to a broad distribution of apparent (observed) Ly{alpha} luminosity for a given intrinsic Ly{alpha} luminosity. Radiative transfer also causes frequency diffusion of Ly{alpha} photons. The resultant Ly{alpha} line is asymmetric with a red tail. The peak of the Ly{alpha} line shifts toward longer wavelength and the shift is anti-correlated with the apparent-to-intrinsic Ly{alpha} luminosity ratio. The simple radiative transfer model provides a new framework for studying LAEs. It is able to explain an array of observed properties of z {approx} 5.7 LAEs in Ouchi et al., producing Ly{alpha} spectra, morphology, and apparent Ly{alpha} luminosity function (LF) similar to those seen in observation. The broad distribution of apparent Ly{alpha} luminosity at fixed UV luminosity provides a natural explanation for the observed UV LF, especially the turnover toward the low luminosity end. The model also reproduces the observed distribution of Ly{alpha} equivalent width (EW) and explains the deficit of UV bright, high EW sources. Because of the broad distribution of the apparent-to-intrinsic Ly{alpha} luminosity ratio, the model predicts effective duty cycles and Ly{alpha} escape fractions for LAEs.},
doi = {10.1088/0004-637X/716/1/574},
url = {https://www.osti.gov/biblio/21451133}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 716,
place = {United States},
year = {Thu Jun 10 00:00:00 EDT 2010},
month = {Thu Jun 10 00:00:00 EDT 2010}
}