O CAESAR: The Optical CAtalogue of Extragalactic SupernovA Remnants
  We present O CAESAR, the Optical CAtalogue of Extragalactic SupernovA
Remnants. O CAESAR will provide the largest homogeneous optical survey of
extragalactic SNR candidates taken by the same telescope, the same instrument,
and under similar observational conditions. Our sample is volume-limited (D
$\leq$ 10 Mpc) and includes mostly galaxies ($\sim$40) from the Large Program
SIGNALS. The Observations are carried out using SITELLE, the imaging Fourier
transform spectrograph of the Canada-France-Hawaii Telescope. Using three
filters, we are able to measure the strong emission lines [O II]$\lambda$3727,
H$\beta$, [O III]$\lambda\lambda$4959,5007, H$\alpha$, [N
II]$\lambda\lambda$6548,6583, and [S II]$\lambda\lambda$6716,6731.
Identification of the SNR candidates will be done automatically and will be
based on four criteria for regions where the emission lines flux ratio [S
II]/H$\alpha$ $\ge$ 0.4. To confirm the shock-heated nature of the ionization
mechanism in the candidates derived from our sample, we adopted a
self-consistent spectroscopic analysis using the whole set of emission lines
available with our SITELLE data and considering Sabbadin plots and BPT
diagrams. We here present our method and first results for the spiral galaxy
NGC 3344.
