EXTENDED Ly{alpha} EMISSION AROUND STAR-FORMING GALAXIES

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/739/2/62; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21587491

Zheng, Zheng ^[1]; Renyue, Cen ^[2]; Weinberg, David ^[3]; Trac, Hy ^[4]; Miralda-Escude, Jordi ^[5]

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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. Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)
4. Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)
5. Institucio Catalana de Recerca i Estudis Avancats, Barcelona (Spain)

Ly{alpha} photons that escape the interstellar medium of star-forming galaxies may be resonantly scattered by neutral hydrogen atoms in the circumgalactic and intergalactic media, thereby increasing the angular extent of the galaxy's Ly{alpha} emission. We present predictions of this extended, low surface brightness Ly{alpha} emission based on radiative transfer modeling in a cosmological reionization simulation. The extended emission can be detected from stacked narrowband images of Ly{alpha} emitters (LAEs) or of Lyman break galaxies (LBGs). Its average surface brightness profile has a central cusp, then flattens to an approximate plateau beginning at an inner characteristic scale below {approx}0.2 Mpc (comoving), then steepens again beyond an outer characteristic scale of {approx}1 Mpc. The inner scale marks the transition from scattered light of the central source to emission from clustered sources, while the outer scale marks the spatial extent of scattered emission from these clustered sources. Both scales tend to increase with halo mass, UV luminosity, and observed Ly{alpha} luminosity. The extended emission predicted by our simulation is already within reach of deep narrowband photometry using large ground-based telescopes. Such observations would test radiative transfer models of emission from LAEs and LBGs, and they would open a new window on the circumgalactic environment of high-redshift star-forming galaxies.

• OSTI ID: 21587491
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 739; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BRIGHTNESS
EMISSION
ENERGY TRANSFER
GALAXIES
HEAT TRANSFER
LUMINOSITY
LYMAN LINES
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIANT HEAT TRANSFER
RED SHIFT
SCATTERING
SIMULATION