The Effect of Bars on the Ionized ISM: Optical Emission Lines from Milky
  Way Analogs
  Gas interior to the bar of the Milky Way has recently been shown as the
closest example of a Low Ionization (Nuclear) Emission Region--LI(N)ER--in the
universe. To better understand the nature of this gas, a sample of face-on
galaxies with integral field spectroscopy are used to study the ionized gas
conditions of 240 barred and 250 nonbarred galaxies, focusing on those that are
most similar to the Milky Way. Strong optical line emission of $[NII]$ $\lambda
6584$, H$\alpha$, $[OIII]$ $\lambda 5007$, and H$\beta$ are used to diagnose
the dominant ionization mechanisms of gas across galaxies and the Galaxy via
Baldwin-Phillips-Terlevich (BPT) Diagrams. Barred galaxies show a strong
suppression of star formation and an increase in composite and LI(N)ER like
spectra in their inner regions when compared with similar nonbarred
counterparts. This effect is lessened in galaxies of very low
($\log_{10}(M_\star/M_\odot) \lesssim 10.4$) or very high
($\log_{10}(M_\star/M_\odot) \gtrsim 11.1$) total stellar mass. Bar masks from
Galaxy Zoo:3D show the bar's non-axisymmetric effect on the ionized gas and
help predict the face-on distribution of ionized gas conditions near the bar of
the Milky Way.
