DUST OBSCURATION IN LYMAN BREAK GALAXIES AT z {approx} 4

Journal Article · Wed Oct 20 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/722/2/1051· OSTI ID:21464648

Ho, I-Ting; Wang, Wei-Hao ^[1]; Morrison, Glenn E ^[2]

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1. Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China)
2. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)

Measuring star formation rates (SFRs) in high-z galaxies with their rest-frame ultraviolet (UV) continuum can be uncertain because of dust obscuration. Prior studies had used the submillimeter emission at 850 {mu}m to determine the intrinsic SFRs of rest-frame UV-selected galaxies, but the results suffered from the low sensitivity and poor resolution ({approx}15''). Here, we use ultradeep Very Large Array 1.4 GHz images with {approx}1''-2'' resolutions to measure the intrinsic SFRs. We perform stacking analyses in the radio images centered on {approx}3500 Lyman break galaxies (LBGs) at z {approx} 4 in the Great Observatories Origins Deep Survey-North and South fields selected with Hubble Space Telescope/Advanced Camera for Surveys data. The stacked radio flux is very low, 0.08 {+-} 0.15 {mu}Jy, implying a mean SFR of 6 {+-} 11 M{sub sun} yr{sup -1}. This is comparable to the uncorrected mean UV SFRs of {approx}5 M{sub sun} yr{sup -1}, implying that the z {approx} 4 LBGs have little dust extinction. The low SFR and dust extinction support the previous results that z {approx} 4 LBGs are in general not submillimeter galaxies. We further show that there is no statistically significant excess of dust-hidden star-forming components within {approx}22 kpc from the LBGs.

• OSTI ID: 21464648
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 722; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DUSTS
ELECTROMAGNETIC RADIATION
EMISSION
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
RADIATIONS
RED SHIFT
STARS
TELESCOPES
ULTRAVIOLET RADIATION