SHELLQs-JWST: Revealing the Spectra of Extended Emission in 12 z > 6 Quasar Host Galaxies Using the JWST NIRSpec Fixed Slit

We present an analysis of the rest-frame optical JWST NIRSpec Fixed Slit spectra of extended host galaxy emission in 12 moderate luminosity quasars from the Subaru High-z Exploration of Low-Luminosity Quasars sample at redshifts 6.0 < z < 6.4. We fit and subtract a point-spread model based on observations of a calibration star and use it to remove the quasar from the 2D spectra, leaving only extended emission, which we analyze. Ten of 12 systems show spatially extended line emission, and six of 12 systems show an extended stellar continuum. From the extended [O III]λ5008 emission line, we measure a 132 ± 22 km s⁻¹ ionized outflow in one system and 52 ± 12 km s⁻¹ rotation, suggesting a coherent disk, in another. From the extended narrow Hα emission, which we hypothesize is ionized by star-forming regions rather than the quasar, we measure star formation rates ranging from ∼7 to 111 M_⊙ yr⁻¹, the majority of which are consistent with the star-forming main sequence (SFMS) at z ≈ 6. The positions of our host galaxies on the (Formula presented) log10[OIII]λ5008/Hβ versus (Formula presented) log10[NII]6584/Hα (R3N2) Baldwin–Phillips–Terlevich diagram indicate ionization rates typical of active galactic nucleus (AGN) activity in the low-redshift Universe, but are consistent with the placement of other z ≈ 6 quasar host galaxies, suggesting that the R3N2 line ratios cannot distinguish AGN- and star-formation-powered line emission at high redshifts. We conclude from the consistency between our quasar host sample with z ∼ 6 galaxies that the presence of a low-luminosity AGN causes little significant change in the properties of galaxies at z ≈ 6 on 10 Myr timescales.