  We investigate the Tully-Fisher Relation (TFR) for a morphologically and
kine- matically diverse sample of galaxies from the SAMI Galaxy Survey using 2
dimensional spatially resolved Halpha velocity maps and find a well defined
relation across the stellar mass range of 8.0 < log(M*) < 11.5. We use an
adaptation of kinemetry to parametrise the kinematic Halpha asymmetry of all
galaxies in the sample, and find a correlation between scatter (i.e. residuals
off the TFR) and asymmetry. This effect is pronounced at low stellar mass,
corresponding to the inverse relationship between stellar mass and kinematic
asymmetry found in previous work. For galaxies with log(M*) < 9.5, 25 +/- 3%
are scattered below the root mean square (RMS) of the TFR, whereas for galaxies
with log(M*) > 9.5 the fraction is 10 +/- 1% We use 'simulated slits' to
directly compare our results with those from long slit spectroscopy and find
that aligning slits with the photometric, rather than the kinematic, position
angle, increases global scatter below the TFR. Further, kinematic asymmetry is
correlated with misalignment between the photometric and kinematic position
angles. This work demonstrates the value of 2D spatially resolved kinematics
for accurate TFR studies; integral field spectroscopy reduces the
underestimation of rotation velocity that can occur from slit positioning off
the kinematic axis.
