2005ApJ...623..763P

This paper presents sensitive new observations of the fine-structure line ³P₂⟶³P₁(J=2-1) of the neutral atomic carbon C I (ν_rest∼809 GHz) in the strongly lensed ultraluminous infrared galaxy (ULIRG) IRAS F10214+4724 at z=2.3 obtained with the millimeter/submillimeter James Clerk Maxwell telescope (JCMT). These do not confirm the presence of emission from this line at the flux levels or angular extent previously reported in the literature. The new 2 σ upper limits are S_CI_≲7Jy.km/s (central position), and <S_CI_>≲8.5Jy/km/s (average over the two Δα=0", Δδ=±10" positions). C I emission assumed to be fully concomitant with the bulk of H₂and confined entirely within the strongly lensed object yields an upper limit of M_CI_(H2_)≲1.5x1010^M_☉, compatible with the reported CO-derived H₂gas mass, within the uncertainties of the two methods. A comparison is made with the recent detection of the ³P₁⟶³P₀(J=1-0) line in this galaxy by Weiss et al., and the large discrepancy with the previous C I measurements is briefly discussed.