We propose to study clustering properties of AGNs at z∼3 to put new constraints on AGN triggering mechanisms through an HSC NB imaging survey. Theoretical models predict that if AGNs are all triggered by gas-rich major mergers, the clustering signal at small-scale (< a few 100 kpc) should show an excess compared to the expectation from an extrapolation of the larger scale correlation function. This trend is indeed confirmed at lower redshift (z<3) with bright SDSS binary QSO sample, but not well constrained at higher redshift. Since secular processes such as disk instability might be more important at z∼3, where the accretion rate of cold gas peaks, the dominant AGN triggering mechanism would be different especially in low-luminosity AGNs. On the other hand, recent discoveries of multiple AGNs with 3 or more AGNs strongly suggest the importance of interactions and large-scale structure. Thus we conduct a survey for AGNs, LAEs, and LBGs at z∼3 in the COSMOS field to derive AGN auto- and cross-correlation functions with LAEs/LBGs. Our strategy to derive their accurate redshift with 4 adjacent NB filters enables sufficiently robust measurement of clustering signals for the first time at z∼3.
This document was translated from LATEX by HEVEA.