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abstract: |
    This is the third paper of a series describing the Asiago-ESO/RASS QSO survey (AERQS), a project aimed at the construction of an all-sky statistically well-defined sample of relatively bright QSOs ($B\le 
    15$) at $z\le 0.3$. We present here the clustering analysis of the full spectroscopically identified database (392 AGN). The clustering signal at $0.02<z<0.22$ is detected at a $3-4\sigma$ level and its amplitude is measured to be $r_0=8.6\pm 2.0 h^{-1}$ Mpc (in a $\Lambda 
    CDM$ model). The comparison with other classes of objects shows that low-redshift QSOs are clustered in a similar way to Radio Galaxies, EROs and early-type galaxies in general, although with a marginally smaller amplitude. The comparison with recent results from the 2QZ shows that the correlation function of QSOs is constant in redshift or marginally increasing toward low redshift. We discuss this behavior with physically motivated models, deriving interesting constraints on the typical mass of the dark matter halos hosting QSOs, $M_{\rm 
    DMH}\sim 10^{12.7} h^{-1} {M_{\odot}}$ ($10^{12.0}-10^{13.5}h^{-1} M_{\odot}$ at 1$\sigma$ confidence level). Finally, we use the clustering data to infer the physical properties of local AGN, obtaining $M_{\rm 
    BH}\sim 2\cdot 10^8 h^{-1} {M_{\odot}}$ ($10^7-3\cdot 10^9 h^{-1} {M_{\odot}}$) for the mass of the active 