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Arxiv: GA-NIFS: JWST/NIRSpec IFS view of the z~3.5 galaxy GS5001 and its close environment at the core of a large-scale overdensity Published: 6/14/2024 9:00:58 PM Updated: 6/14/2024 9:00:58 PM

Paper abstract: We present JWST NIRSpec observations in IFS mode of the galaxy GS5001 atredshift z=3.47, the brightest member of a candidate protocluster in theGOODS-S field. The data cover a field of view (FoV) of 4''\times4''(~30\times30~kpc^2) and were obtained as part of the GA-NIFS GTO program.The observations include both high (R~2700) and low (R~100) spectral resolutiondata, spanning the rest-frame wavelength ranges 3700-6780A and 1300-11850A,respectively. We analyse the spatially resolved ionised gas kinematics andinterstellar medium properties, including obscuration, gas metallicity,excitation, ionisation parameter, and electron density. In addition to thecentral galaxy, the NIRSpec FoV covers three components in the south, withvelocities blue-shifted by -150 km/s with respect to the main galaxy, andanother source in the north redshifted by ~200 km/s. The emission line ratiosin the BPT diagram are consistent with star formation for all the sources inthe FoV. We measure electron densities of ~500 cm^{-3} in the differentsources. The gas-phase metallicity in the main galaxy is 12+log(O/H) =8.45\pm0.04, and slightly lower in the companions (12+log(O/H) = 8.34-8.42),consistent with the mass-metallicity relation at z~3. We find peculiarline ratios (high log [NII]/H\alpha, low log [OIII]/H\beta) in the northernpart of the main galaxy (GS5001). These could be attributed to either highermetallicity, or to shocks resulting from the interaction of the main galaxywith the northern source. We identify a spatially resolved outflow in the maingalaxy, with an extension of about 3 kpc. We find maximum outflow velocities of~400 km/s, an outflow mass of (1.7\pm0.4)\times 10^8 M_{\odot}, a massoutflow rate of 23\pm5 M_{\odot} yr^{-1} and a mass loading factor of0.23. These properties are compatible with star formation being the driver ofthe outflow.