We present the first optical identification and confirmation of a sample of supernova remnants ( SNRs ) in the nearby galaxy NGC 3344 .
Using high spectral and spatial resolution data , obtained with the CFHT imaging Fourier transform spectrograph SITELLE , we identified about 2200 emission line regions , many of which are H \sevensize II regions , diffuse ionized gas regions , and also SNRs .
Considering the stellar population and diffuse ionized gas background , that are quite important in NGC 3344 , we have selected 129 SNR candidates based on four criteria for regions where the emission lines flux ratio [ S \sevensize II ] /H \alpha \geq 0.4 .
Emission lines of [ O \sevensize II ] \lambda 3727 , H \beta , [ O \sevensize III ] \lambda \lambda 4959,5007 , H \alpha , [ N \sevensize II ] \lambda \lambda 6548,6583 , and [ S \sevensize II ] \lambda \lambda 6716,6731 have been measured to study the ionized gas properties of the SNR candidates .
We adopted a self-consistent spectroscopic analysis , based on Sabbadin plots and BPT diagrams , to confirm the shock-heated nature of the ionization mechanism in the candidates sample .
With this analysis , we end up with 42 Confirmed SNRs , 45 Probable SNRs , and 42 Less likely SNRs .
Using shock models , the Confirmed SNRs seems to have a metallicity ranging between LMC and 2 \times solar .
We looked for correlations between the size of the Confirmed SNRs and their emission lines ratios , their galaxy environment , and their galactocentric distance : we see a trend for a metallicity gradient among the SNR population , along with some evolutionary effects .