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We describe new JWST/NIRSpec observations of galaxies at $z\gtrsim7$ takenfrom the CEERS survey. Previous observations of this area have revealedassociations of Ly$\alpha$ emitters at redshifts ($z=7.5$, $7.7$, $8.7$) wherethe intergalactic medium (IGM) is thought to be mostly neutral, leading tosuggestions that these systems are situated in large ionized bubbles. Weidentify 21 $z\gtrsim7$ galaxies with robust redshifts in the CEERS dataset,including 10 in the Ly$\alpha$ associations. Their spectra are indicative ofvery highly ionized and metal poor gas, with line ratios (O32 $=17.84$ andNe3O2 $=0.89$, linear scale) and metallicity ($12+\log{(\rm{O/H})}=7.84$) thatare rarely seen at lower redshifts. We find that the most extreme spectralproperties are found in the six $z\gtrsim7$ Ly$\alpha$ emitters in the sample.Each has a hard ionizing spectrum indicating that their visibility is likelyenhanced by efficient ionizing photon production. Ly$\alpha$ velocity offsetsare found to be very large ($\gtrsim300$ km s$^{-1}$), likely also contributingto their detectability. We find that Ly$\alpha$ in $z\gtrsim7$ galaxies is$6-12\times$ weaker than in lower redshift samples with matched rest-opticalspectral properties. If the bubbles around the Ly$\alpha$ emitters arerelatively small ($\lesssim0.5-1$ pMpc), we may expect such significantattenuation of Ly$\alpha$ in these ionized regions. We discuss several othereffects that may contribute to weaker Ly$\alpha$ emission at $z\gtrsim7$. Deepspectroscopy of fainter galaxies in the vicinity of the Ly$\alpha$ emitterswill better characterize the physical scale of the ionized bubbles in thisfield.

JWST/NIRSpec Spectroscopy of $z=7-9$ Star Forming Galaxies with CEERS: New Insight into Bright Ly$\alpha$ Emitters in Ionized Bubbles