Dust Properties of C II Detected z ∼ 5.5 Galaxies: New HST/WFC3 Near-IR Observations
Abstract
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_(FIR)/L_(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.
Additional Information
© 2017 The American Astronomical Society. Received 2017 March 17; revised 2017 May 19; accepted 2017 July 6; published 2017 August 9. D.R. and R.P. acknowledge support from the National Science Foundation under grant number AST-1614213 to Cornell University. R.P. acknowledges support through award SOSPA3-008 from the NRAO. V.S. acknowledges support from the European Union's Seventh Frame-work program under grant agreement 337595 (ERC Starting Grant, "CoSMass"). Based on observations made with the NASA/ESA Hubble Space Telescope, obtained (from the Data Archive) at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13641 and #13384. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2012.1. 00523.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.Attached Files
Published - Barisic_2017_ApJ_845_41.pdf
Submitted - 1707.02980.pdf
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Additional details
- Eprint ID
- 80025
- Resolver ID
- CaltechAUTHORS:20170809-140222043
- NSF
- AST-1614213
- National Radio Astronomy Observatory (NRAO)
- SOSPA3-008
- European Research Council (ERC)
- 337595
- NASA
- NAS 5-26555
- W. M. Keck Foundation
- NASA/JPL/Caltech
- Created
-
2017-08-09Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- COSMOS, Infrared Processing and Analysis Center (IPAC), Astronomy Department