Abstract
We present a catalog of 59 z ≈ 4.5 Lyα-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Area Lya (LALA) narrowband imaging survey. We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of ∼76%. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z ≈ 4.5 Lyαemitting galaxies in the ≈0.7deg2 covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the confirmed Lya lines have rest-frame equivalent widths (Wγrest) that exceed the maximum predicted for normal stellar populations: 17%-31% (93% confidence) of the detected galaxies show Wγrest > 190 Å, and 12%-27% (90%) confidence) show Wγrest > 240 ÅWe construct a luminosity function of z ≈ 4.5 Lyα emission lines for comparison to Lyα luminosity functions spanning 3.1 < z < 6.6. We find no significant evidence for Lyα luminosity function evolution from z ≈ 3 to z ≈ 6. This result supports the conclusion that the intergalactic medium remains largely reionized from the local universe out to z ≈ 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z ∼ 3 and z ∼ 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations.
Original language | English (US) |
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Pages (from-to) | 1227-1240 |
Number of pages | 14 |
Journal | Astrophysical Journal |
Volume | 671 |
Issue number | 2 |
DOIs | |
State | Published - Dec 20 2007 |
Keywords
- Cosmology: observations
- Early universe
- Galaxies: evolution
- Galaxies: formation
- Galaxies: high-redshift
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science
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Ly{alpha} galaxies at z~4.5
Dawson, S. (Creator), Rhoads, J. E. (Creator), Malhotra, S. (Creator), Stern, D. (Creator), Wang, J. (Creator), Dey, A. (Creator), Spinrad, H. (Creator), Jannuzi, B. T. (Creator) & Stern, D. (Creator), Strasbourg Astronomical Data Center, 2010
DOI: 10.26093/cds/vizier.16711227, https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/671/1227
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