The Large-scale Environments of Low-luminosity AGNs at 3.9 < z < 6 and Implications for Their Host Dark Matter Halos from a Complete NIRCam Grism Redshift Survey

Abstract We study the large-scale environments and clustering properties of 28 low-luminosity active galactic nuclei (AGNs) at z = 3.9–6 in the GOODS-N field. Our sample, identified from the JWST NIRCam Imaging and WFSS data in Complete NIRCam Grism Redshift Survey and First Reionization Epoch Spectroscopically Complete Observations surveys with either broad H α emission lines or V-shaped continua, are compared to 782 H α emitters (HAEs) selected from the same data. These AGNs are located in diverse large-scale environments and do not preferentially reside in denser environments compared to HAEs. Their overdensity field, δ , averaged over (15 h −1 cMpc) 3 , ranges from −0.56 to 10.56, and shows no clear correlation with broad-line luminosity, black hole (BH) masses, or the AGN fraction. It suggests that >10 cMpc structures do not significantly influence BH growth. We measure the two-point cross-correlation function of AGNs with HAEs, finding a comparable amplitude to that of the HAE autocorrelation. This indicates similar bias parameters and host dark matter halo masses for AGNs and HAEs. The correlation length of field AGNs is 4.26 h −1 cMpc and 7.66 h −1 cMpc at 3.9 < z < 5 and 5 < z < 6, respectively. We infer a median host dark matter halo mass of log ( M h / M ⊙ ) ≈ 11.0 − 11.2 and host stellar masses of log ( M ⋆ / M ⊙ ) ≈ 8.4 – 8.6 by comparing with the U niverse M achine simulation. Our clustering analysis suggests that low-luminosity AGNs at high redshift reside in normal star-forming galaxies with overmassive BHs. They represent an intrinsically distinct population from luminous quasars and could be a common phase in galaxy evolution.