LYMAN BREAK GALAXIES AT z approx 5: REST-FRAME UV SPECTRA. III

Journal Article · Sat Oct 10 00:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/704/1/117· OSTI ID:21367461

Kajino, Hiroki; Ohta, Kouji; Yabe, Kiyoto; Yuma, Suraphong ^[1]; Iwata, Ikuru ^[2]; Akiyama, Masayuki ^[3]; Tamura, Naoyuki; Aoki, Kentaro ^[4]; Sawicki, Marcin ^[5]

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1. Department of Astronomy, Kyoto University, Kyoto 606-8502 (Japan)
2. Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Okayama 719-0232 (Japan)
3. Astronomical Institute, Tohoku University, Sendai 980-77 (Japan)
4. Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 (United States)
5. Department of Astronomy and Physics, St. Mary's University, 923 Robie St., Halifax, Nova Scotia, B3H 3C3 (Canada)

We present results of optical spectroscopic observations of candidates of Lyman break galaxies (LBGs) at z approx 5 in the region, including the GOODS-N and the J0053+1234 regions by using Gemini Multi-Object Spectrograph North and South, respectively. Among 25 candidates, five objects are identified to be at z approx 5 (two of them were already identified by an earlier study) and one object very close to the color-selection window turned out to be a foreground galaxy. With this spectroscopically identified sample and those from previous studies, we derived the lower limits on the number density of bright (M{sub UV} < -22.0 mag) LBGs at z approx 5. These lower limits are comparable to or slightly smaller than the number densities of UV luminosity functions (UVLFs) that show the smaller number density among z approx 5 UVLFs in literature. However, by considering that there remain many LBG candidates without spectroscopic observations, the number density of bright LBGs is expected to increase by a factor of two or more. The evidence for the deficiency of UV luminous LBGs with large Lyalpha equivalent widths was reinforced. We discuss possible causes for the deficiency and prefer the interpretation of dust absorption.

• OSTI ID: 21367461
• Journal Information: Astrophysical Journal, Vol. 704, Issue 1; Other Information: DOI: 10.1088/0004-637X/704/1/117; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
COLOR
DUSTS
GALACTIC EVOLUTION
GALAXIES
LUMINOSITY
RED SHIFT
ULTRAVIOLET SPECTRA
EVOLUTION
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHYSICAL PROPERTIES
SORPTION
SPECTRA