Extended Data Fig. 1: Kinematic position angle.
From: An increase in black hole activity in galaxies with kinematically misaligned gas

Result of the kinematic position angle (PA) determination for one of the galaxies in the sample, J145002.16+003443.6, or ID 93807 in the SAMI catalogue. Left: Map of stellar velocity with title Vstar. The best fit kinematic PA is shown by the green solid line. The value determined is PAstellar = 184.0 ± 1. 5∘ where the error corresponds to the 3σ uncertainties of the fit. Right: Map of gas velocity with title Vgas. The best fit kinematic PA is shown by the green solid line, PAgas = 4 ± 4∘. The PA orientation is measured from North (PA = 0, up in the figure) to East and is per our definition oriented from the approaching (blueshifted) to the receding (redshifted) regions of the map. The dashed black line shows the zero velocity line, which is the axis that fit_kinematic_pa uses to create the mirrored bi(anti)symmetric velocity map. The measured misalignment between the stellar and gas kinematic angles for this galaxy, ΔPA = ∣PAstellar - PAgas∣ = 180∘, corresponds to counter-rotation of gas and stars.