High-z galaxies with JWST and local analogues — it is not only star formation

Abstract I present an analysis of the JWST NIRSpec data SMACS 0723 released as Early Release Observations. As part this three new redshifts are provided, bringing total reliable to 14. propose a modification direct abundance determination method that reduces sensitivity flux calibration uncertainties by factor ∼3 and show resulting abundances in good agreement with Bayesian photoionization models rest-frame optical spectrum. also 6355 is most likely narrow-line active galactic nucleus (AGN) M* < 109 M⊙ at z = 7.66, argue 10612 might have AGN contribution its through comparison low-redshift analogues. Under assumption lines come from star-formation find galaxies gas depletion times ∼107 years, comparable similar locally. identify population possibly shock-dominated 3 whose near-IR emission plausibly nearly all shocks discuss their implications. close discussion potential for biases mass-metallicity relation using samples defined detected [O iii]4363 low-z can lead up 0.5 dex systematic trend mass.