Spectroscopic redshift of CEERS-21

Determine the spectroscopic redshift of CEERS-21 to establish whether it is physically associated with C3PO-84478 and assess its possible contribution to the ionizing-photon budget of the surrounding region.

Background

CEERS-21 is identified near C3PO-84478 on the basis of a photometric redshift of zphot = 9.01 ± 0.30. Although it was observed with JWST NIRSpec medium gratings, no robust emission line was detected, so its spectroscopic redshift is unresolved. Establishing the redshift is necessary to determine whether CEERS-21 is physically associated with C3PO-84478 and whether it could contribute materially to the local ionized environment.

References

It was observed with JWST\ NIRSpec medium gratings as part of the CEERS survey; however, no robust emission line was detected, and the spectroscopic redshift remains unconstrained.

— C3PO: A Lyα Emitting Galaxy at $z \sim 9$  (2609.03608 - Hu et al., 3 Sep 2026) in Section 4.2, “Environment of C3PO-84478”