3D Optical Spectroscopic Study of NGC 3344 with SITELLE: I. Identification and Confirmation of Supernova Remnants
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 128 SNR candidates based on four criteria that include the well known emission lines flux ratio [SII]/Hα ≥ 0.4. Emission lines of [OII] λ3727, Hβ, [OIII] λλ4959, 5007, Hα, [NII] λλ6549, 6584, and [SII] λλ6717, 6731 have been measured to study the ionized gas properties of the SNR candidates. We adopted a self-consistent spectroscopic analysis, based on Sabaddin 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 35 Confirmed SNRs, 20 Probable SNRs, and 73 Less likely SNRs. Using shock models, the Confirmed SNRs seems to have shock velocities below 250 km/s and a metallicity somewhat equivalent or higher to the LMC. We do not find correlations between the size of the confirmed SNRs (with a diameter between 40 and 120 pc) and their emission lines ratios, but we see a gradient within the galaxy for the ratios [NII]/Hα and [SII]/Hα.
Supernova Remnants: An Odyssey in Space after Stellar Death II
- Pub Date:
- June 2019