Sensitive new observations of the fine structure line ^ { 3 } P _ { 2 } \rightarrow ^ { 3 } P _ { 1 } ( J=2–1 ) of the neutral atomic carbon CI ( \nu _ { rest } \sim 809 GHz ) in the strongly lensed Ultra Luminous Infrared Galaxy ( ULIRG ) IRAS F10214+4724 at z=2.3 with the mm/sub-mm telescope James Clerk Maxwel ( JCMT ) are presented .
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 \sigma upper limits are : S _ { CI } \lesssim 7 Jy km s ^ { -1 } ( central position ) , and \langle S _ { CI } \rangle \lesssim 8.5 Jy km s ^ { -1 } ( average over the two [ \delta ( RA ) , \delta ( Dec ) ] = [ 0 ^ { \prime \prime } , \pm 10 ^ { \prime \prime } ] positions ) .
A CI emission assumed fully concomitant with the bulk of H _ { 2 } and confined entirely within the strongly lensed object yields an upper limit of M _ { CI } ( H _ { 2 } ) \lesssim 1.5 \times 10 ^ { 10 } M _ { \odot } , compatible with the reported CO-derived H _ { 2 } gas mass , within the uncertainties of the two methods .
A comparison with the recent detection of the ^ { 3 } P _ { 1 } \rightarrow ^ { 3 } P _ { 0 } ( J=1–0 ) line in this galaxy by Weiss et al .
( 2004 ) is made and the large discrepancy with the previous CI measurements is briefly discussed .