MSA-3D: A Diversity of Dust Attenuation Profiles Across the Epoch of Thin Disk Emergence

Year: 2026

Type: preprint

Abstract: We present spatially resolved measurements of dust attenuation and star formation in 18 main-sequence star-forming galaxies at z$\sim$1 from the MSA-3D survey, obtained by mapping the Balmer emission lines at $\sim$1 kpc resolution with JWST/NIRSpec's MSA in a slit-stepping strategy. We investigate the diversity of radial attenuation profiles, and how the spatial variation affects attenuation and star formation rates (SFR) derived from single-aperture measurements. We find a notable diversity among radial attenuation profiles: some galaxies exhibit centrally peaked attenuation, but the majority exhibit flat or even positive radial profiles, with large variation at a fixed stellar mass. This diversity may reflect different evolutionary pathways shaped by various mechanisms such as disk settling, merging, and internal processes. We examine possible biases arising from single-aperture and integrated measurements and find that, while they can under- or over-estimate attenuation and SFRs for individual galaxies, the sample-averaged trends remain roughly unchanged, with the derived SFRs consistent with the star-forming main sequence, and a small scatter. From our sample, we find a median stellar-to-nebular reddening ratio f = E(B-V)$_{\rm star}$/E(B-V)$_{\rm gas}$ of 0.88 with an interquartile range of 0.51-0.96, suggesting relatively uniform dust distributions even in intermediate-mass galaxies (stellar masses $\sim 10^9$-$10^{10.5}~M_{\odot}$). Our results highlight the importance of spatially resolved attenuation measurements for accurately tracing star formation and understanding the evolving dust geometry in galaxies during a critical epoch of morphological transformation.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2609.19298

Authors: Barišić, Ivana, Jones, Tucker, Reddy, Naveen, Malkan, Matthew, Sanders, Ryan, Henry, Alaina, Acharyya, Ayan, Bundy, Kevin, Salcedo, Juan M. Espejo, Glazebrook, Karl, Nanayakkara, Themiya, Obreschkow, Danail, Roy, Namrata, Tsukui, Takafumi, Vulcani, Benedetta, Wang, Xin

Institutions: University of California, Davis, University of California, Riverside, University of California, Los Angeles, University of Kentucky, Space Telescope Science Institute, Osservatorio Astronomico di Padova, University of California, Santa Cruz, Max Planck Institute for Extraterrestrial Physics, Swinburne University of Technology, The University of Sydney, The University of Western Australia, International Centre for Radio Astronomy Research, Raman Research Institute, Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, National Aeronautics and Space Administration, Space Telescope Science Institute, European Commission, National Natural Science Foundation of China, Japan Society for the Promotion of Science, Fundamental Research Funds for the Central Universities

OpenAlex ID: W7213576926