MSA-3D: Metallicity Gradients in Galaxies at $z\sim1$ with JWST/NIRSpec Slit-stepping Spectroscopy

Mengting Ju, Xin Wang, Tucker Jones, Ivana Barišić, Themiya Nanayakkara, Kevin Bundy, Claude-André Faucher-Giguère, Shuai Feng, Karl Glazebrook, Alaina Henry, Matthew A. Malkan, Danail Obreschkow, Namrata Roy, Ryan L. Sanders, Xunda Sun, Tommaso Treu, Qianqiao Zhou

Published 2024-09-03, updated 2024-12-13Version 2

The radial gradient of gas-phase metallicity is a powerful probe of the chemical and structural evolution of star-forming galaxies, closely tied to disk formation and gas kinematics in the early universe. We present spatially resolved chemical and dynamical properties for a sample of 25 galaxies at $0.5 \lesssim z \lesssim 1.7$ from the \msasd survey. These innovative observations provide 3D spectroscopy of galaxies at a spatial resolution approaching JWST's diffraction limit and a high spectral resolution of $R\simeq2700$. The metallicity gradients measured in our galaxy sample range from $-$0.03 to 0.02 dex~kpc$^{-1}$. Most galaxies exhibit negative or flat radial gradients, indicating lower metallicity in the outskirts or uniform metallicity throughout the entire galaxy. We confirm a tight relationship between stellar mass and metallicity gradient at $z\sim1$ with small intrinsic scatter of 0.02 dex~kpc$^{-1}$. Our results indicate that metallicity gradients become increasingly negative as stellar mass increases, likely because the more massive galaxies tend to be more ``disky". This relationship is consistent with the predictions from cosmological hydrodynamic zoom-in simulations with strong stellar feedback. This work presents the effort to harness the multiplexing capability of JWST NIRSpec/MSA in slit-stepping mode to map the chemical and kinematic profiles of high-redshift galaxies in large samples and at high spatial and spectral resolution.