FIRST SPECTROSCOPIC MEASUREMENTS OF [O III] EMISSION FROM Ly{alpha} SELECTED FIELD GALAXIES AT z {approx} 3.1

Journal Article · Fri Apr 01 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/730/2/136· OSTI ID:21574805

McLinden, Emily M; Rhoads, James E; Malhotra, Sangeeta; Hibon, Pascale; Richardson, Mark L. A. ^[1]; Finkelstein, Steven L ^[2]; Cresci, Giovanni ^[3]; Quirrenbach, Andreas ^[4]; Pasquali, Anna ^[5]; Fuyan, Bian; Xiaohui, Fan ^[6]; Woodward, Charles E ^[7]

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1. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)
2. George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, 4242 TAMU, College Station, TX 77843 (United States)
3. INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)
4. ZAH, Landessternwarte, Universitaet Heidelberg, Koenigstuhl 12, D-69117 Heidelberg (Germany)
5. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
6. Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
7. Department of Astronomy, 351 Tate Laboratory of Physics, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States)

We present the first spectroscopic measurements of the [O III] 5007 A line in two z {approx} 3.1 Ly{alpha} emitting galaxies (LAEs) using the new near-infrared instrument LUCIFER1 on the 8.4 m Large Binocular Telescope. We also describe the optical imaging and spectroscopic observations used to identify these LAEs. Using the [O III] line we have measured accurate systemic redshifts for these two galaxies, and discovered a velocity offset between the [O III] and Ly{alpha} lines in both, with the Ly{alpha} line peaking 342 and 125 km s{sup -1} redward of the systemic velocity. These velocity offsets imply that there are powerful outflows in high-redshift LAEs. They also ease the transmission of Ly{alpha} photons through the interstellar medium and intergalactic medium around the galaxies. By measuring these offsets directly, we can refine both Ly{alpha}-based tests for reionization, and Ly{alpha} luminosity function measurements where the Ly{alpha} forest affects the blue wing of the line. Our work also provides the first direct constraints on the strength of the [O III] line in high-redshift LAEs. We find [O III] fluxes of 7 and 36 x10{sup -17} erg s{sup -1} cm{sup -2} in two z {approx} 3.1 LAEs. These lines are strong enough to dominate broadband flux measurements that include the line (in this case, K{sub s} -band photometry). Spectral energy distribution fits that do not account for the lines would therefore overestimate the 4000 A (and/or Balmer) break strength in such galaxies, and hence also the ages and stellar masses of such high-z galaxies.

• OSTI ID: 21574805
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 730; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ELEMENTS
EMISSION
ENERGY SPECTRA
GALAXIES
INTERGALACTIC SPACE
LUMINOSITY
LYMAN LINES
NONMETALS
OPTICAL PROPERTIES
OXYGEN
PHYSICAL PROPERTIES
RED SHIFT
SPACE
SPECTRA
VELOCITY