Planetary Nebula Luminosity Function distances for 19 galaxies observed
  by PHANGS-MUSE
  We provide new planetary nebula luminosity function (PNLF) distances to 19
nearby spiral galaxies that were observed with VLT/MUSE by the PHANGS
collaboration. Emission line ratios are used to separate planetary nebulae
(PNe) from other bright [OIII] emitting sources like compact supernovae
remnants (SNRs) or HII regions. While many studies have used narrowband imaging
for this purpose, the detailed spectral line information provided by integral
field unit (IFU) spectroscopy grants a more robust way of categorising
different [OIII] emitters. We investigate the effects of SNR contamination on
the PNLF and find that we would fail to classify all objects correctly, when
limited to the same data narrowband imaging provides. However, the few
misclassified objects usually do not fall on the bright end of the luminosity
function, and only in three cases does the distance change by more than
$1\sigma$. We find generally good agreement with literature values from other
methods. Using metallicity constraints that have also been derived from the
same IFU data, we revisit the PNLF zero point calibration. Over a range of
$8.34 < 12 + \log(\mathrm{O}/\mathrm{H}) < 8.59$, our sample is consistent with
a constant zero point and yields $M^*=-4.542^{+0.103}_{-0.059}\, \mathrm{mag}$,
within $1\sigma$ of other literature values. MUSE pushes the limits of PNLF
studies and makes galaxies beyond $20\, \mathrm{Mpc}$ accessible for this kind
of analysis. This approach to the PNLF shows great promise for leveraging
existing archival IFU data on nearby galaxies.
