Dust Properties of C ii Detected z ∼ 5.5 Galaxies: New HST/WFC3 Near-IR Observations

Journal Article · Thu Aug 10 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA7EDA· OSTI ID:22875943

Barisic, I.; Smolcic, V. ^[1]; Faisst, A. L.; Capak, P. L. ^[2]; Pavesi, R.; Riechers, D. A. ^[3]; Scoville, N. Z. ^[4]; Cooke, K.; Kartaltepe, J. S. ^[5]

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1. Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb (Croatia)
2. Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)
3. Department of Astronomy, Cornell University, Space Sciences Building, Ithaca, NY 14853 (United States)
4. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
5. School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623 (United States)

We examine the rest-frame ultraviolet (UV) properties of 10 [C ii]λ158 μm-detected galaxies at z ∼ 5.5 in COSMOS using new Hubble Space Telescope/Wide Field Camera 3 near-infrared imaging. Together with pre-existing 158 μm continuum and [C ii] line measurements by the Atacama Large Millimeter/submillimeter Array, we study their dust attenuation properties on the IRX–β diagram, which connects the total dust emission (∝ IRX=log(L{sub FIR}/L{sub 1600})) to the line-of-sight dust column (∝ β). We find systematically bluer UV continuum spectral slopes (β) compared to previous low-resolution ground-based measurements, which relieves some of the tension between models of dust attenuation and observations at high redshifts. While most of the galaxies are consistent with local starburst or Small Magellanic Cloud–like dust properties, we find galaxies with low IRX values and a large range in β that cannot be explained by models of a uniform dust distribution well mixed with stars. A stacking analysis of Keck/DEIMOS optical spectra indicates that these galaxies are metal-poor with young stellar populations that could significantly alter their spatial dust distribution.

• OSTI ID: 22875943
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 845; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPARATIVE EVALUATIONS
COSMIC DUST
DISTRIBUTION
EMISSION
GALACTIC EVOLUTION
MAGELLANIC CLOUDS
RED SHIFT
SPACE
SPECTRA
STARS
TELESCOPES
ULTRAVIOLET RADIATION
UNIVERSE