Dust in the Average Galaxy: Attenuation, Emission, and Opacity from 0<z<7
We present constraints on the dust emission and attenuation properties of galaxies across 0<z<7 using JWST imaging from the COSMOS-Web Survey combined with deep FIR/(sub)millimeter data from Spitzer, Herschel, SCUBA-2, NIKA-2 and ALMA. We analyze over 500,000 galaxies to independently constrain attenuation in the rest-frame ultraviolet (UV) and optical as well as dust emission from stacked FIR spectral energy distributions (SEDs), enabling a direct comparison between the two. We find UV/optical attenuation systematically underpredicts IR luminosity by a factor of ~3x at 0.5<z<7 and up to an order of magnitude for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⋆</mml:mo> </mml:msub> <mml:mo>></mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>10.5</mml:mn> </mml:msup> <mml:msub> <mml:mi>M</mml:mi> <mml:mo>⊙</mml:mo> </mml:msub> </mml:mrow> </mml:math> . We derive empirical relationships for the effective attenuation, dust temperature, fraction of star formation that is unobscured, and dust-to-stellar mass ratio as functions of redshift and stellar mass. We separate the first order effect of star/dust geometry from dust grain properties by combining constraints on the IR SED, UV SED, and dust mass surface density. Importantly, we measure over an order of magnitude decrease in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>U</mml:mi> <mml:mi>V</mml:mi> </mml:mrow> </mml:msub> <mml:mi>/</mml:mi> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>F</mml:mi> <mml:mi>I</mml:mi> <mml:mi>R</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> –the ratio of dust mass absorption coefficients in the UV at 1600Å and FIR at 500 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>μ</mml:mi> </mml:math> m–from z~0 to z~7. A depressed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>U</mml:mi> <mml:mi>V</mml:mi> </mml:mrow> </mml:msub> <mml:mi>/</mml:mi> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>F</mml:mi> <mml:mi>I</mml:mi> <mml:mi>R</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> is consistent with a deficit of small dust grains, possibly attributable to the intense radiation fields of high- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>z</mml:mi> </mml:math> star formation; indeed, we find a redshift-invariant inverse relationship between <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>U</mml:mi> <mml:mi>V</mml:mi> </mml:mrow> </mml:msub> <mml:mi>/</mml:mi> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>F</mml:mi> <mml:mi>I</mml:mi> <mml:mi>R</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msub> <mml:mi>Σ</mml:mi> <mml:mrow> <mml:mi>S</mml:mi> <mml:mi>F</mml:mi> <mml:mi>R</mml:mi> </mml:mrow> </mml:msub> </mml:math> . Most evolution in the dust-to-stellar ratio is at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mi>z</mml:mi> <mml:mo><</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> , the product of mild downward evolution in the dust-to-gas ratio combined with steep evolution in the gas-to-stellar ratio. The significant evolution and dynamic range of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>U</mml:mi> <mml:mi>V</mml:mi> </mml:mrow> </mml:msub> <mml:mi>/</mml:mi> <mml:msub> <mml:mi>κ</mml:mi> <mml:mrow> <mml:mi>F</mml:mi> <mml:mi>I</mml:mi> <mml:mi>R</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> and prevailing disconnect between the UV/optical and FIR regimes emphasize that direct dust constraints are irreplaceable for the majority of star-forming galaxies at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mi>z</mml:mi> <mml:mo><</mml:mo> <mml:mn>7</mml:mn> </mml:mrow> </mml:math> , not just the most extreme star-formers.
Authors
- Seiji Fujimoto (ORCID: https://orcid.org/0000-0001-7201-5066)
- Marko Shuntov (ORCID: https://orcid.org/0000-0002-7087-0701)
- G. Gozaliasl (ORCID: https://orcid.org/0000-0002-0236-919X)
- L. Moscardini (ORCID: https://orcid.org/0000-0002-3473-6716)
- Nicole E. Drakos (ORCID: https://orcid.org/0000-0003-4761-2197)
- Anton M. Koekemoer (ORCID: https://orcid.org/0000-0002-6610-2048)
- Caitlin M. Casey (ORCID: https://orcid.org/0000-0002-0930-6466)
- Desika Narayanan (ORCID: https://orcid.org/0000-0002-7064-4309)
- Brant E. Robertson (ORCID: https://orcid.org/0000-0002-4271-0364)
- Manuel Aravena (ORCID: https://orcid.org/0000-0002-6290-3198)
- Laura Sommovigo (ORCID: https://orcid.org/0000-0002-2906-2200)
- Sinclaire M. Manning (ORCID: https://orcid.org/0000-0003-0415-0121)
- Andreas L. Faisst (ORCID: https://orcid.org/0000-0002-9382-9832)
- Aswin P. Vijayan
- Ali Hadi (ORCID: https://orcid.org/0009-0003-3097-6733)
- Michaela Hirschmann (ORCID: https://orcid.org/0000-0002-3301-3321)
- Dhruv Zimmerman
- Maximilien Franco
- Louise Paquereau
- Richard Massey
- Georgios E. Magdis
- Andrew J. Battisti
- Can Xu
- Wuji Wang
- Santosh Harish
- Jason Rhodes
- Jacqueline E. McCleary
- Felix Martinez
- Claudia Scarlata
- Claudia del P. Lagos
- Daizhong Liu
- Yingjie Cheng
- Ronaldo Laishram
- Henry Joy McCracken
- Jeyhan S. Kartaltepe
- Olivier Ilbert
- Hollis B. Akins
- Arianna S. Long
- Crystal L. Martin
- Kohei Inayoshi
- Erini Lambrides
- Jorge A. Zavala
- Jed McKinney
- Hiddo Algera
- Rasha M. Samir
- Ezequiel Treister
Publication Details
- Journal
- The Open Journal of Astrophysics
- Published
- 2026-08-18
- DOI
- https://doi.org/10.33232/001c.167549
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00