Excess AGN activity in the z= 2.30 Protocluster in HS 1700+64

摘要: We present the results of spectroscopic, narrow-band and X-ray observations a z= 2.30 protocluster in field QSO HS 1700+643. Using sample BX/MD galaxies, which are selected to be at z ~ 2.2–2.7 by their rest-frame ultraviolet colours, we find that there five AGN have been identified characteristic emission-lines optical/near-IR spectra; this represents an enhancement over significant >98.5 per cent confidence. ~200-ks Chandra/ACIS-I observation detect total 161 point sources Poissonian false-probability limit 4 × 10^(−6) identify eight these with galaxies. Two spectroscopically confirmed members also classified as emission-line AGN. When compared similarly sample, analysis indicates is evidence for field, >99 Deep Lyα imaging reveals 4/123 emitters (LAEs) found associated sources, two one highly likely member. do not activity LAE (result only 87 confidence). The emitting fractions samples 6.9^(+9.2)_(−4.4) 2.9^(+2.9)_(−1.6) cent, respectively, L_(2-10 keV)≥ 4.6 10^(43) erg s^(−1) 2.30. These findings similar from 3.09 SSA 22 Lehmer et al. (2009), both suggest favoured dense environments > 2.