The HDUV Survey: A Revised Assessment of the Relationship between UV Slope and Dust Attenuation for High-redshift Galaxies

By Naveen A. Reddy, P. Oesch, R. Bouwens, M. Montes, G. Illingworth, C. Steidel, P. V. van Dokkum, H. Atek, M. Carollo, A. Cibinel and 6 more. 2017

156 citations recorded by the source corpus.

We use a newly assembled sample of 3545 star-forming galaxies with secure spectroscopic, grism, and photometric redshifts at z = 1.5–2.5 to constrain the relationship between UV slope (β) and dust attenuation (LIR/LUV ≡ IRX). Our sample significantly extends the range of LUV and β probed in previous UV-selected samples, including those as faint as M1600 = −17.4 ( ) and −2.6 ≲ β ≲ 0.0. IRX is measured using stacks of deep Herschel data, and the results are compared with predictions of the IRX−β relation for different assumptions of the stellar population model and obscuration curve. We find that z = 1.5–2.5 galaxies have an IRX−β relation that is consistent with the predictions for an SMC curve if we invoke subsolar-metallicity models currently favored for high-redshift galaxies, while the commonly assumed starburst curve overpredicts the IRX at a given β by a factor of ≳3. IRX is roughly constant with LUV for LUV ≳ 3 × 109 L⊙. Thus, the commonly observed trend of fainter galaxies having bluer β may simply reflect bluer intrinsic slopes for such galaxies, rather than lower obscurations. The IRX−β relation for young/low-mass galaxies at z ≳ 2 implies a dust curve that is steeper than the SMC. The lower attenuations and higher ionizing photon output for low-metallicity stellar populations point to Lyman continuum production efficiencies, ξion, that may be elevated by a factor of ≈2 relative to the canonical value for L* galaxies, aiding in their ability to keep the universe ionized at z ∼ 2.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/11f551e6a1aea4ae024f53d9890c95358f6f15be

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. M. Boquien
2. C. Conroy
3. D. Burgarella
4. L. Ciesla
5. S. Tacchella
6. V. Buat
7. S. Bose
8. C. Mason

In Instrumentation

1. M. Boquien
2. C. Conroy
3. D. Burgarella
4. V. Buat
5. S. Tacchella
6. L. Ciesla
7. S. Bose
8. P. Oesch

Citations in the corpus

• CIGALE: a python Code Investigating GALaxy Emission (2018, background): “…works have found and tried to explain the extensive variations observed in the IRX-β relation over the years (e.g. Kong et al. 2004; Burgarella et al. 2005; Boquien et al. 2009, 2012; Overzier et al. 2011; Grasha et al. 2013; Ye et al. 2016; Popping et al. 2017; Reddy et al. 2018, and many others).”
• Rapid Reionization by the Oligarchs: The Case for Massive, UV-bright, Star-forming Galaxies with High Escape Fractions (2019, methodology): “…the strong nebular fluxes, high ionization lines, and extreme line widths that are now known to be ubiquitous at z∼2.5–3.5 (e.g., Holden et al. 2016; Steidel et al. 2016; Reddy et al. 2018b) and also commonly seen at z>6 (e.g., Stark et al. 2015; RobertsBorsani et al. 2016; Mainali et al. 2017).”