THE STELLAR POPULATION AND STAR FORMATION RATES OF z Almost-Equal-To 1.5-1.6 [O II]-EMITTING GALAXIES SELECTED FROM NARROWBAND EMISSION-LINE SURVEYS

Journal Article · Thu Sep 20 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/757/1/63· OSTI ID:22092257

Ly, Chun ^[1]; Malkan, Matthew A.; Ross, Nathaniel R. ^[2]; Kashikawa, Nobunari; Hayashi, Masao ^[3]; Nagao, Tohru ^[4]; Shimasaku, Kazuhiro ^[5]; Ota, Kazuaki ^[6]

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1. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
2. Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States)
3. Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo (Japan)
4. The Hakubi Project, Kyoto University, Kyoto (Japan)
5. Department of Astronomy, School of Science, University of Tokyo, Bunkyo, Tokyo (Japan)
6. Department of Astronomy, Kyoto University, Kyoto (Japan)

We present the first detailed study of the stellar populations of star-forming galaxies at z {approx} 1.5, which are selected by their [O II] emission line, detected in narrowband surveys. We identified {approx}1300 [O II] emitters at z = 1.47 and z = 1.62 in the Subaru Deep Field with rest-frame equivalent widths (EWs) above 13 A. Optical and near-infrared spectroscopic observations for Almost-Equal-To 10% of our samples show that our separation of [O II] from [O III] emission-line galaxies in two-color space is 99% successful. We analyze the multi-wavelength properties of a subset of {approx}1200 galaxies with the best photometry. They have average rest-frame EW of 45 A, stellar mass of 3 Multiplication-Sign 10{sup 9} M{sub Sun }, and stellar age of 100 Myr. In addition, our spectral energy distribution (SED) fitting and broadband colors indicate that [O II] emitters span the full range of galaxy populations at z {approx} 1.5. We also find that 80% of [O II] emitters are also photometrically classified as 'BX/BM' (UV) galaxies and/or the star-forming 'BzK' (near-IR) galaxies. Our [O II] emission line survey produces a far more complete and somewhat deeper sample of z {approx} 1.5 galaxies than either the BX/BM or sBzK selection alone. We constructed average SEDs and find that higher [O II] EW galaxies have somewhat bluer continua. SED model-fitting shows that they have on average half the stellar mass of galaxies with lower [O II] EW. The observed [O II] luminosity is well correlated with the far-UV continuum with a logarithmic slope of 0.89 {+-} 0.22. The scatter of the [O II] luminosity against the far-UV continuum suggests that [O II] can be used as a star formation rate indicator with a reliability of 0.23 dex.

• OSTI ID: 22092257
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 757; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
COLOR
ENERGY SPECTRA
GALAXIES
LUMINOSITY
MASS
NEAR INFRARED RADIATION
OXYGEN IONS
PHOTOMETRY
PHOTON EMISSION
RED SHIFT
SPACE
STAR EVOLUTION
STARS
ULTRAVIOLET RADIATION