TOZZI, PaoloPaoloTOZZI0000-0003-3096-9966PENTERICCI, LauraLauraPENTERICCI0000-0001-8940-6768GILLI, RobertoRobertoGILLI0000-0001-8121-6177Pannella, M.M.PannellaFIORE, FabrizioFabrizioFIORE0000-0002-4031-4157Miley, G.G.MileyNONINO, MarioMarioNONINO0000-0001-6342-9662Rottgering, H. J. A.H. J. A.RottgeringStrazzullo, V.V.StrazzulloAnderson, C. S.C. S.AndersonBORGANI, STEFANOSTEFANOBORGANI0000-0001-6151-6439Calabro', A.A.Calabro'Carilli, C.C.CarilliDannerbauer, H.H.DannerbauerDi Mascolo, L.L.Di MascoloFeruglio, ChiaraChiaraFeruglio0000-0002-4227-6035Gobat, R.R.GobatJin, S.S.JinLiu, A.A.LiuMroczkowski, T.T.MroczkowskiNorman, C.C.NormanRASIA, ELENAELENARASIA0000-0003-4175-002XRosati, P.P.RosatiSARO, ALEXANDROALEXANDROSARO0000-0002-9288-862X2022-03-242022-03-2420220004-6361http://hdl.handle.net/20.500.12386/31873(Abridged) We present an analysis of the 700 ks Chandra ACIS-S observation of the field around the Spiderweb Galaxy at z=2.156, focusing on the nuclear activity in the associated large-scale environment. We identify unresolved X-ray sources down to flux limits of 1.3X10^{-16} and 3.9X10^{-16} erg/s/cm^2 in the soft and hard band, respectively. We search for counterparts in the optical, NIR and submm bands to identify X-ray sources belonging to the protocluster. We detect 107 X-ray unresolved sources within 5 arcmin (corresponding to 2.5 Mpc) of J1140-2629, among which 13 have optical counterparts with spectroscopic redshift 2.11<z<2.20, and 1 source with photometric redshift consistent with this range. Our X-ray spectral analysis shows that their intrinsic spectral slope is consistent with an average <\Gamma>~1.84+-0.04. The best-fit intrinsic absorption for 5 protocluster X-ray members is N_H>10^{23} cm^{-2}, while other 6 have upper limits of the order of fewX10^{22} cm^{-2}. Two sources can only be fitted with very flat \Gamma<=1, and are therefore considered Compton-thick candidates. Their 0.5-10 keV rest frame luminosities are larger than 2X10^{43} erg/s, significantly greater than X-ray luminosities expected from star formation activity. The X-ray luminosity function of AGN in the volume associated to the Spiderweb protocluster in the range 10^{43}<L_X<10^{44.5} erg/s, is at least 10 times higher than that in the field at the same redshift and significantly flatter. The X-ray AGN fraction is measured to be (25.5+-4.5)% in the stellar mass range log(M*/M_sun)>10.5, corresponding to an enhancement of 6.0^{+9.0}_{-3.0} with respect to the COSMOS field at comparable redshifts and stellar mass range. We conclude that the galaxy population in the Spiderweb Protocluster is characterized by enhanced X-ray nuclear activity triggered by environmental effects on Mpc scales.STAMPAenArticlehttp://arxiv.org/abs/2203.02208v1FIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation