The SAMI Galaxy Survey: Can we trust aperture corrections to predict
  star formation?
  In the low redshift Universe (z<0.3), our view of galaxy evolution is
primarily based on fibre optic spectroscopy surveys. Elaborate methods have
been developed to address aperture effects when fixed aperture sizes only probe
the inner regions for galaxies of ever decreasing redshift or increasing
physical size. These aperture corrections rely on assumptions about the
physical properties of galaxies. The adequacy of these aperture corrections can
be tested with integral-field spectroscopic data. We use integral-field spectra
drawn from 1212 galaxies observed as part of the SAMI Galaxy Survey to
investigate the validity of two aperture correction methods that attempt to
estimate a galaxy's total instantaneous star formation rate. We show that
biases arise when assuming that instantaneous star formation is traced by
broadband imaging, and when the aperture correction is built only from spectra
of the nuclear region of galaxies. These biases may be significant depending on
the selection criteria of a survey sample. Understanding the sensitivities of
these aperture corrections is essential for correct handling of systematic
errors in galaxy evolution studies.
