Extended Data Fig. 3: Fraction of galaxies with a specific excitation mechanism divided by morphology.
From: An increase in black hole activity in galaxies with kinematically misaligned gas

Fraction of galaxies with a specific excitation mechanism, as a function of the misalignment between the stellar and the gas kinematic angle (ΔPA = ∣PAstars - PAgas∣) and the galaxy morphology. The histogram bars of each colour add up to 1 across the ΔPA distribution. The top panel shows the total population, the bottom left panel shows the early type galaxies and the bottom right panel shows the late type galaxies in the sample. Each panel is colour coded as a function of the main excitation mechanism in the galaxies. The panels can be understood as, for example how galaxies with emission lines from AGN, LINERs or young stars are distributed as a function of ΔPA. Almost all the late type galaxies in the sample are aligned, while early-type galaxies show a broader distribution in terms of ΔPA. Most of the misaligned galaxies have AGN or LINER as their excitation mechanism. Excitation by star formation only, in early type galaxies tends to occur mostly in aligned ΔPA < 45∘, with a smaller secondary peak in close to counter-rotating ΔPA ~ 180∘ galaxies. The fraction of star forming early-type galaxies in the fourth bin (135∘≤ΔPA ≤180∘) is marginally higher than the fraction of star forming early-type galaxies in the second and third bins at the 68% and 95% confidence level, respectively.