Galaxies Going Bananas: Inferring the 3D Geometry of High-redshift Galaxies with JWST-CEERS

Authors

• Viraj Pandya, Columbia University
• Haowen Zhang, The University of Arizona
• Marc Huertas-Company, Simons Foundation
• Kartheik G. Iyer, Columbia University
• Elizabeth McGrath, Colby College
• Guillermo Barro, University of the PacificFollow
• Steven L. Finkelstein, The University of Texas at Austin
• Martin Kümmel, Ludwig-Maximilians-Universität München
• William G. Hartley, University of Geneva
• Henry C. Ferguson, Space Telescope Science Institute
• Jeyhan S. Kartaltepe, Rochester Institute of Technology
• Joel Primack, University of California, Santa Cruz
• Avishai Dekel, Hebrew University of Jerusalem
• Sandra M. Faber, Lick Observatory
• David C. Koo, Lick Observatory
• Greg L. Bryan, Columbia University
• Rachel S> Somerville, Simons Foundation
• Ricardo O. Amorín, Universidad de La Serena
• Pablo Arrabal Haro, NOIRLab
• Micaela B. Bagley, The University of Texas at Austin
• Eric F. Bell, University of Michigan, Ann Arbor

Document Type

Article

Publication Title

Astrophysical Journal

Department

Physics

ISSN

15384357

Volume

963

Issue

1

DOI

10.3847/1538-4357/ad1a13

First Page

1

Last Page

34

Publication Date

2-28-2024

Abstract

The 3D geometries of high-redshift galaxies remain poorly understood. We build a differentiable Bayesian model and use Hamiltonian Monte Carlo to efficiently and robustly infer the 3D shapes of star-forming galaxies in James Webb Space Telescope Cosmic Evolution Early Release Science observations with log M * / M ⊙ = 9.0 - 10.5 at z = 0.5-8.0. We reproduce previous results from the Hubble Space Telescope Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey in a fraction of the computing time and constrain the mean ellipticity, triaxiality, size, and covariances with samples as small as ∼50 galaxies. We find high 3D ellipticities for all mass-redshift bins, suggesting oblate (disky) or prolate (elongated) geometries. We break that degeneracy by constraining the mean triaxiality to be ∼1 for log M * / M ⊙ = 9.0 - 9.5 dwarfs at z > 1 (favoring the prolate scenario), with significantly lower triaxialities for higher masses and lower redshifts indicating the emergence of disks. The prolate population traces out a “banana” in the projected b / a - log a diagram with an excess of low-b/a, large- log a galaxies. The dwarf prolate fraction rises from ∼25% at z = 0.5-1.0 to ∼50%-80% at z = 3-8. Our results imply a second kind of disk settling from oval (triaxial) to more circular (axisymmetric) shapes with time. We simultaneously constrain the 3D size-mass relation and its dependence on 3D geometry. High-probability prolate and oblate candidates show remarkably similar Sérsic indices (n ∼ 1), nonparametric morphological properties, and specific star formation rates. Both tend to be visually classified as disks or irregular, but edge-on oblate candidates show more dust attenuation. We discuss selection effects, follow-up prospects, and theoretical implications.

Creative Commons License

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

Recommended Citation

Pandya, Viraj; Zhang, Haowen; Huertas-Company, Marc; Iyer, Kartheik G.; McGrath, Elizabeth; Barro, Guillermo; Finkelstein, Steven L.; Kümmel, Martin; Hartley, William G.; Ferguson, Henry C.; Kartaltepe, Jeyhan S.; Primack, Joel; Dekel, Avishai; Faber, Sandra M.; Koo, David C.; Bryan, Greg L.; Somerville, Rachel S>; Amorín, Ricardo O.; Arrabal Haro, Pablo; Bagley, Micaela B.; and Bell, Eric F., "Galaxies Going Bananas: Inferring the 3D Geometry of High-redshift Galaxies with JWST-CEERS" (2024). Pacific Faculty Work. 96.
https://scholarlycommons.pacific.edu/all-faculty/96