Efficient Ionizers with Low H β + [O iii ] Equivalent Widths: JADES Spectroscopy of a Peculiar High-redshift Population

Acknowledgements: This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under grant No. 2137424. M.V.M. is supported by the National Science Foundation via AAG grant 2205519, the Wisconsin Alumni Research Foundation via grant MSN251397, and NASA via STScI grant JWST-GO-4426. E.C.L. acknowledges the support of an STFC Webb Fellowship (ST/W001438/1). A.J.B. acknowledges funding from the “FirstGalaxies” Advanced Grant from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant Agreement No. 789056). S.T. acknowledges support from the Royal Society Research grant G125142. Y.Z. acknowledges support from the JWST/NIRCam contract to the University of Arizona NAS5-02015. J.W. gratefully acknowledges support from the Cosmic Dawn Center through the DAWN Fellowship. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant No. 140. S.C. acknowledges support by European Union’s HE ERC Starting grant No. 101040227—WINGS. C.S. acknowledges support from the Science and Technology Facilities Council (STFC), by the ERC through Advanced grant 695671 “QUENCH” and by the UKRI Frontier Research grant RISEandFALL.