2023MNRAS.518.2088M

It is still a matter of intense debate how supermassive black holes (SMBHs) grow and the role played by feedback from active galactic nuclei (AGN) in the coevolution of SMBHs and galaxies. To test the coevolution proposed by theoretical models, we compile a large AGN sample of 5639 X-ray detected AGN, over a wide redshift range, spanning nearly three orders of magnitude in X-ray luminosity. The AGN have been detected in the COSMOS-Legacy, the Boötes, the XMM-XXL, and the eROSITA Final Equatorial Depth Survey (eFEDS) fields. Using the specific star formation rate estimates, we split the AGN host galaxies into star forming (SF), starburst (SB), and quiescent (Q). Our results show that the AGN accretion is increased in SB systems compared to SF and Q. Our analysis reveals a mild increase of L_X with M_*. The L_X/star formation rate (SFR) ratio has a weak dependence on M_* and at fixed M_* it is highest in Q systems. The latter trend is mostly driven by the significant drop in SFR in the Q state. The measured strong variations in SFR from the SB/SF to Q mirror those predicted in merger models with AGN feedback. However, the observed mild variations in L_X are at variance with the same models. We also study the evolution of SFR for a galaxy control sample and found that it is very similar to that of X-ray AGN. This suggests that either AGN play a minor role in the star formation quenching, or the relative timescales of the two processes are different.