Ly{alpha} EMISSION FROM HIGH-REDSHIFT SOURCES IN COSMOS

Journal Article · Sat Dec 01 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/760/2/128· OSTI ID:22086208

Mallery, Ryan P; Mobasher, Bahram; Hemmati, Shoubaneh ^[1]; Capak, Peter; Kakazu, Yuko; Masters, Dan; Scoville, Nick ^[2]; Ilbert, Olivier; LeFevre, Olivier ^[3]; Scarlata, Claudia ^[4]; Salvato, Mara ^[5]; McCracken, Henry ^[6]

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1. Department of Physics and Astronomy, University of California, Riverside, 900 University Ave, Riverside, CA 92507 (United States)
2. NASA/JPL Spitzer Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
3. Laboratoire d'Astrophysique de Marseille, CNRS-Universite de Provence, 38 rue Frederic Joliot-Curie, F-13388 Marseille Cedex 13 (France)
4. School of Physics and Astronomy, University of Minnesota, 116 Church St, Minneapolis, MN 55455 (United States)
5. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
6. Institut d'Astrophysique de Paris, UMR7095 CNRS, Universite Pierre et Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France)

We investigate spectroscopically measured Ly{alpha} equivalent widths (EWs) and escape fractions of 244 sources of which 95 are Lyman break galaxies (LBGs) and 106 Lyman alpha emitters (LAEs) at z {approx} 4.2, z {approx} 4.8, and z {approx} 5.6 selected from intermediate and narrowband observations. The sources were selected from the Cosmic Evolution Survey and observed with the DEIMOS spectrograph. We find that the distribution of EWs shows no evolution with redshift for both the LBG selected sources and the intermediate/narrowband LAEs. We also find that the Ly{alpha} escape fraction of intermediate/narrowband LAEs is on average higher and has a larger variation than the escape fraction of LBG selected sources. The escape fraction does not show a dependence with redshift. Similar to what has been found for LAEs at low redshifts, the sources with the highest extinctions show the lowest escape fractions. The range of escape fractions increases with decreasing extinction. This is evidence that the dust extinction is the most important factor affecting the escape of Ly{alpha} photons, but at low extinctions other factors, such as the H I covering fraction and gas kinematics, can be just as effective at inhibiting the escape of Ly{alpha} photons.

• OSTI ID: 22086208
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 760; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
COSMIC DUST
COSMIC PHOTONS
GALACTIC EVOLUTION
GALAXIES
HYDROGEN
LYMAN LINES
PHOTON EMISSION
RED SHIFT
UNIVERSE