No Clear Submillimeter Signature of Suppressed Star Formation Among X-Ray Luminous Active Galactic Nuclei

Many theoretical models require powerful active galactic nuclei (AGNs) to suppress star formation in distant galaxies and reproduce the observed properties of today's massive galaxies. A recent study based on Herschel -SPIRE submillimeter observations claimed to provide direct support for this picture, reporting a significant decrease in the mean star formation rates (SFRs) of the most luminous AGNs ( L X >10 44 erg s −1 ) at z ≈ 1–3 in the Chandra Deep Field-North (CDF-N). In this Letter, we extend these results using Herschel -SPIRE 250 μm data in the COSMOS and Chandra Deep Field-South fields to achieve an order-of-magnitude improvement in the number of sources at L X >10 44 erg s −1 . On the basis of our analysis, we find no strong evidence for suppressed star formation in L X >10 44 erg s −1 AGNs at z ≈ 1–3. The mean SFRs of the AGNs are constant over the broad X-ray luminosity range of L X ≈10 43 –10 45 erg s −1 (with mean SFRs consistent with typical star-forming galaxies at z ≈ 2; 〈SFRs〉 ≈ 100–200 M ☉ yr −1 ). We suggest that the previous CDF-N results were likely due to low number statistics. We discuss our results in the context of current theoretical models.