Spectroscopic Confirmation of CEERS NIRCam-selected Galaxies at z ≃ 8–10

Abstract We present JWST/NIRSpec prism spectroscopy of seven galaxies selected from Cosmic Evolution Early Release Science (CEERS) survey NIRCam imaging with photometric redshifts z phot > 8. measure emission line = 7.65 and 8.64 for two galaxies. For other sources without securely detected lines we z = 9.77 − 0.29 + 0.37 ${10.01}_{-0.19}^{+0.14}$?> 10.01 0.19 0.14 by fitting model spectral templates to the data, which detect continuum breaks consistent Ly α opacity a mostly neutral intergalactic medium. The presence strong absence give high confidence that these have 9.6, but redshift values derived alone large uncertainties given low resolution relatively S/N CEERS NIRSpec data. ∼ 10 observed are luminous ( M UV < −20), blue continua (−2.3 ≲ β −1.9) dust attenuation ${A}_{V}\simeq {0.15}_{-0.1}^{+0.3}$?> A V ≃ 0.15 0.1 0.3 ); at least one them has stellar mass galaxy $\mathrm{log}({M}_{\star }/{M}_{\odot })\simeq {9.3}_{-0.3}^{+0.2}$?> log ( M ⋆ stretchy="true">/ ⊙ stretchy="false">) 9.3 0.2 ). Considered together spectroscopic observations NIRCam-selected high- candidates in literature, find rate confirmation confirmed interlopers (8%). Ten out 35 8 do not secure redshifts, their spectra is 9.6. generally agreement (within uncertainties) values, also tend be slightly overestimated (〈Δ 〉 0.45 ± 0.11), suggesting current fully describe very-high- sources. Overall, solidifies evidence spatial density bright compared theoretical predictions, further disfavors an accelerated decline integrated luminosity