An Updated Dust-to-Star Geometry: Dust Attenuation Does Not Depend on Inclination in 1.3 ≤z ≤2.6 Star-forming Galaxies from MOSDEF

Authors

• Brian Lorenz, University of California, Berkeley
• Mariska Kriek, Sterrewacht Leiden
• Alice E. Shapley, University of California, Los Angeles
• Naveen A. Reddy, University of California, Riverside
• Ryan L. Sanders, University of California, Davis
• Guillermo Barro, University of the PacificFollow
• Alison L. Coil, University of California, San Diego
• Bahram Mobasher, University of California, Riverside
• Sedona H. Price, University of Pittsburgh
• Jordan N. Runco, University of California, Los Angeles
• Irene Shivaei, The University of Arizona
• Brian Siana, University of California, Riverside
• Daniel R. Weisz, University of California, Berkeley

Document Type

Article

Publication Title

Astrophysical Journal

Department

Physics

ISSN

15384357

Volume

951

Issue

1

DOI

10.3847/1538-4357/accdd1

First Page

1

Last Page

15

Publication Date

6-29-2023

Abstract

We investigate dust attenuation and its dependence on viewing angle for 308 star-forming galaxies at 1.3 ≤ z ≤ 2.6 from the MOSFIRE Deep Evolution Field survey. We divide galaxies with a detected Hα emission line and coverage of Hβ into eight groups by stellar mass, star formation rate (SFR), and inclination (i.e., axis ratio), and we then stack their spectra. From each stack, we measure the Balmer decrement and gas-phase metallicity, and then we compute the median A V and UV continuum spectral slope (β). First, we find that none of the dust properties (Balmer decrement, A V, or β) varies with the axis ratio. Second, both stellar and nebular attenuation increase with increasing galaxy mass, showing little residual dependence on SFR or metallicity. Third, nebular emission is more attenuated than stellar emission, and this difference grows even larger at higher galaxy masses and SFRs. Based on these results, we propose a three-component dust model in which attenuation predominantly occurs in star-forming regions and large, dusty star-forming clumps, with minimal attenuation in the diffuse ISM. In this model, nebular attenuation primarily originates in clumps, while stellar attenuation is dominated by star-forming regions. Clumps become larger and more common with increasing galaxy mass, creating the above mass trends. Finally, we argue that a fixed metal yield naturally leads to mass regulating dust attenuation. Infall of low-metallicity gas increases the SFR and lowers the metallicity, but leaves the dust column density mostly unchanged. We quantify this idea using the Kennicutt-Schmidt and fundamental metallicity relations, showing that galaxy mass is indeed the primary driver of dust attenuation.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Lorenz, Brian; Kriek, Mariska; Shapley, Alice E.; Reddy, Naveen A.; Sanders, Ryan L.; Barro, Guillermo; Coil, Alison L.; Mobasher, Bahram; Price, Sedona H.; Runco, Jordan N.; Shivaei, Irene; Siana, Brian; and Weisz, Daniel R., "An Updated Dust-to-Star Geometry: Dust Attenuation Does Not Depend on Inclination in 1.3 ≤z ≤2.6 Star-forming Galaxies from MOSDEF" (2023). Pacific Faculty Work. 140.
https://scholarlycommons.pacific.edu/all-faculty/140