We present gas-phase radial metallicity profiles for 20 main-sequence galaxies at 4 < z < 6 primarily based on JWST NIRSpec IFU observations obtained as part of the JWST-ALPINE-CRISTAL programme. Our study aims to connect the metallicity gradients of these galaxies with their kinematic properties from [C II] 158 mu m ALMA observations. We mapped the radial profiles of oxygen abundance using the strong-line method, leveraging the rich set of rest-frame optical emission lines. Linear fits to the annular-binned radial profiles show that, on average, the metallicity gradients are slightly positive with a median of +0.039 +/- 0.010 dex kpc(-1). However, only three galaxies show a gradient > 0.05 dex kpc(-1) at 1 sigma, and none have a significant negative gradient. There are no substantial systematic offsets in gradients when using different line diagnostics. We investigated the correlation between the metallicity gradients and the intrinsic gas velocity dispersion sigma(0) as well as the V-rot/sigma(0) ratio of the disks. Combining our sample with mass-matched literature samples at 3 less than or similar to z less than or similar to 7, we found a negative shallow correlation between V-rot/sigma(0) and the metallicity gradients, but no strong relationships with sigma(0). As V-rot/sigma(0) increases towards later cosmic times, the observed negative trend with V-rot/sigma(0) is consistent with the overall cosmic evolution of metallicity gradients from high to low redshifts. This suggests that disk maturity plays a crucial role in shaping the radial metallicity gradients. We do not find the metallicity gradients of disk galaxies to be significantly different from non-disk galaxies, which could be attributed to the frequent accretion events that took place in these gas-rich systems. Additionally, we find no strong dependence of metallicity gradients on stellar mass and only a marginal positive dependence on specific star-formation rate. Our study extends the efforts to connect the internal kinematics of galaxies with their gas-phase chemical enrichment at kiloparsec scales from cosmic noon to z > 4.
The ALPINE-CRISTAL-JWST Survey: Gas-phase abundance gradients of main-sequence star-forming galaxies and their kinematics at 4 < z < 6
Parlanti E.;Jones G.;Chen J.;Burkert A.;Ferrara A.;Vallini L.;
2026
Abstract
We present gas-phase radial metallicity profiles for 20 main-sequence galaxies at 4 < z < 6 primarily based on JWST NIRSpec IFU observations obtained as part of the JWST-ALPINE-CRISTAL programme. Our study aims to connect the metallicity gradients of these galaxies with their kinematic properties from [C II] 158 mu m ALMA observations. We mapped the radial profiles of oxygen abundance using the strong-line method, leveraging the rich set of rest-frame optical emission lines. Linear fits to the annular-binned radial profiles show that, on average, the metallicity gradients are slightly positive with a median of +0.039 +/- 0.010 dex kpc(-1). However, only three galaxies show a gradient > 0.05 dex kpc(-1) at 1 sigma, and none have a significant negative gradient. There are no substantial systematic offsets in gradients when using different line diagnostics. We investigated the correlation between the metallicity gradients and the intrinsic gas velocity dispersion sigma(0) as well as the V-rot/sigma(0) ratio of the disks. Combining our sample with mass-matched literature samples at 3 less than or similar to z less than or similar to 7, we found a negative shallow correlation between V-rot/sigma(0) and the metallicity gradients, but no strong relationships with sigma(0). As V-rot/sigma(0) increases towards later cosmic times, the observed negative trend with V-rot/sigma(0) is consistent with the overall cosmic evolution of metallicity gradients from high to low redshifts. This suggests that disk maturity plays a crucial role in shaping the radial metallicity gradients. We do not find the metallicity gradients of disk galaxies to be significantly different from non-disk galaxies, which could be attributed to the frequent accretion events that took place in these gas-rich systems. Additionally, we find no strong dependence of metallicity gradients on stellar mass and only a marginal positive dependence on specific star-formation rate. Our study extends the efforts to connect the internal kinematics of galaxies with their gas-phase chemical enrichment at kiloparsec scales from cosmic noon to z > 4.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
