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Dependence of the IRX-β Dust Attenuation Relation on Metallicity and Environment

Shivaei, Irene and Darvish, Behnam and Sattari, Zahra and Chartab, Nima and Mobasher, Bahram and Scoville, Nick and Rieke, George (2020) Dependence of the IRX-β Dust Attenuation Relation on Metallicity and Environment. Astrophysical Journal Letters, 903 (2). Art. No. L28. ISSN 2041-8213. https://resolver.caltech.edu/CaltechAUTHORS:20201106-092350956

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Abstract

We use a sample of star-forming field and protocluster galaxies at z = 2.0–2.5 with Keck/MOSFIRE K-band spectra, a wealth of rest-frame ultraviolet (UV) photometry, and Spitzer/MIPS and Herschel/PACS observations, to dissect the relation between the ratio of infrared (IR) to UV luminosity (IRX) versus UV slope (β) as a function of gas-phase metallicity (12+log(O/H) ~ 8.2–8.7). We find no significant dependence of the IRX-β trend on environment. However, we find that at a given β, IRX is highly correlated with metallicity, and less correlated with mass, age, and specific star formation rate (sSFR). We conclude that, of the physical properties tested here, metallicity is the primary physical cause of the IRX-β scatter, and the IRX correlation with mass is presumably due to the mass dependence on metallicity. Our results indicate that the UV attenuation curve steepens with decreasing metallicity, and spans the full range of slope possibilities from a shallow Calzetti-type curve for galaxies with the highest metallicity in our sample (12+log(O/H) ~ 8.6) to a steep Small Magellanic Cloud (SMC)-like curve for those with 12+log(O/H) ~ 8.3. Using a Calzetti (SMC) curve for the low (high) metallicity galaxies can lead to up to a factor of 3 overestimation (underestimation) of the UV attenuation and obscured star formation rate. We speculate that this change is due to different properties of dust grains present in the interstellar medium of low- and high-metallicity galaxies.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.3847/2041-8213/abc1efDOIArticle
https://arxiv.org/abs/2010.10538arXivDiscussion Paper
ORCID:
AuthorORCID
Shivaei, Irene0000-0003-4702-7561
Darvish, Behnam0000-0003-4919-9017
Sattari, Zahra0000-0002-0364-1159
Chartab, Nima0000-0003-3691-937X
Scoville, Nick0000-0002-0438-3323
Rieke, George0000-0003-2303-6519
Additional Information:© 2020 The American Astronomical Society. Received 2020 October 4; revised 2020 October 16; accepted 2020 October 16; published 2020 November 5. Based on observations made with 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. I.S. thanks Robin Ciardullo and Joel Leja for helpful conversations. I.S. is supported by NASA through the NASA Hubble Fellowship grant # HST-HF2-51420, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555.
Group:Astronomy Department
Funders:
Funding AgencyGrant Number
NASA Hubble FellowshipHST-HF2-51420
NASANAS5-26555
Subject Keywords:Interstellar dust extinction ; Interstellar dust ; Dust continuum emission ; Galaxy evolution ; Chemical abundances ; Galaxy chemical evolution ; Scaling relations ; Galaxy properties ; Galaxy abundances ; Star formation
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Interstellar dust extinction (837); Interstellar dust (836); Dust continuum emission (412); Galaxy evolution (594); Chemical abundances (224); Galaxy chemical evolution (580); Scaling relations (2031)
Record Number:CaltechAUTHORS:20201106-092350956
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201106-092350956
Official Citation:Irene Shivaei et al 2020 ApJL 903 L28
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106472
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:06 Nov 2020 18:03
Last Modified:06 Nov 2020 18:03

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