2015MNRAS.446.2861K

We performed a detailed study of the extended cool gas, traced by Mgii absorption [Wr(2796) ≥ 0.3 Å], surrounding 14 narrow-line active galactic nuclei (AGNs) at 0.12 ≤ z ≤ 0.22 using background quasar sightlines. The background quasars probe the AGNs at projected distances of 60 ≤ D ≤ 265 kpc. We find that, between 100 ≤ D ≤ 200 kpc, AGNs appear to have lower Mgii gas covering fractions (0.09^+0.18_-0.08) than quasars (0.47^+0.16_-0.15) and possibly lower than inactive field galaxies (0.25^+0.11_-0.09). We do not find a statistically significant azimuthal angle dependence for the Mgiicovering fraction around AGNs, though the data hint at one. We also study the `down-the-barrel' outflow properties of the AGNs themselves and detect intrinsic NaiD absorption in 8/8 systems and intrinsic Mgii absorption in 2/2 systems, demonstrating that the AGNs have significant reservoirs of cool gas. We find that 6/8 NaiD and 2/2 Mgii intrinsic systems contain blueshifted absorption with Δv > 50 km/s, indicating outflowing gas. The 2/2 intrinsic Mgii systems have outflow velocities a factor of ∼ 4 higher than the NaiD outflow velocities. Our results are consistent with AGN-driven outflows destroying the cool gas within their haloes, which dramatically decreases their cool gas covering fraction, while starburst-driven winds are expelling cool gas into their circumgalactic media (CGM). This picture appears contrary to quasar-quasar pair studies which show that the quasar CGM contains significant amounts of cool gas whereas intrinsic gas found `down-the-barrel' of quasars reveals no cool gas. We discuss how these results are complementary and provide support for the AGN unified model.