  Using measurements of the [O III], H$\alpha$ and [N II] emission line fluxes
originating in the cool (T $\sim10^4$ K) gas that populates the halos of
massive early-type galaxies with stellar mass greater than $10^{10.4}$
M$_\odot$, we explore the recent conjecture that active galactic nucleus (AGN)
activity preferentially removes the circumgalactic medium (CGM) along the polar
(minor-axis) direction. We find deficits in the mean emission line flux of [O
III] and H$\alpha$ (65 and 43%, respectively) along the polar vs. planar
directions, although due to the large uncertainties in these difficult
measurements the results are of marginal statistical significance
(1.5$\sigma$). More robustly (97 to 99.9% confidence depending on the
statistical test), diagnostic line ratios show stronger AGN ionization
signatures along the polar direction at small radii than at other angles or
radii. Our results are consistent with the conjecture of an anisotropic CGM in
massive, early type galaxies, suggested on independent grounds, that is tied to
AGN activity and begin to show the potential of CGM mapping using emission
lines.

Astrophysics of Galaxies