Year: 2026
Type: preprint
Abstract: Here we present the first systematic search for shocks in six gravitationally lensed galaxies at 2.37 < z < 3.625 with JWST/NIRSpec integral field spectroscopy from the LEnsing and Galaxy Growth: Observing Substructures (LEGGOS) survey. We employ diagnostics that utilize the fluxes and kinematics of shock-sensitive rest-frame optical emission lines H\b{eta}, [O iii] λ5008, [O i] λ6302, Hα, [N ii] λ6585, and [S ii] λλ6718, 6733. We find that, on pixel, clump, and galaxy-integrated scales, the LEGGOS spectra show minimal if any evidence for shocks. The image plane pixels are < 8% within the shock regions of the rest-frame optical line ratio diagnostics for any individual galaxy, and the shock-identified pixels do not show a coherent spatial structure. We also leverage MAPPINGS V shock models to infer shock velocities from the observed emission lines, and find that the distributions of inferred shock velocities are inconsistent with those expected for shock-dominated gas. Altogether, none of these methods provide significant evidence for shocks in the six LEGGOS sources. We conclude by discussing the implications of the lack of evidence for shocks in the broader context of galaxy evolution at cosmic noon and earlier epochs.
Source: arXiv (Cornell University)
Institutions: International Space Science Institute, University of Cincinnati, University of Oslo, University of Arizona, Eureka Scientific, University of Chicago, Pennsylvania State University, Korea Advanced Institute of Science and Technology, University of Washington, Goddard Space Flight Center, Stockholm University, AlbaNova, University of Pittsburgh, University of Michigan
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G4756828217
OpenAlex ID: W7212028306