A ROSAT OBSERVATION OF THE HIGH-REDSHIFT GALAXY IRAS F10214+4724

A 20-ks ROSAT observation of the extremely luminous IRAS galaxy IRAS F 10214+4724 shows a very weak X-ray source, significant only at similar to 2 sigma. This immediately refutes the hypothesis that F10214+4724 is simply a quasar with modest (A(V) similar to 1) line-of-sight redde ning, as we would then have expected thousands of counts. The X-ray ab sorbing column, assuming solar abundances, required to reduce the (red shifted) similar to 3-keV emission to that expected from a normal quas ar is similar to 5 x 10(23) cm(-2). We compare the overall energy dist ribution of F10214+4724 with that of NGC 1068. The optical-UV-X-ray em ission is very closely similar to that of the type 2 Seyfert nucleus o f NGC 1068 (both show S-nu proportional to nu(-2), and very high polar ization), but the IR-millimetre spectrum is a good match to that of th e starburst ring. It seems very likely that F10214+4724, like NGC 1068 , is a composite object.