Kinematics of supernova remnants in two SIGNALS galaxies - NGC 6822 and M33

Salvador Duarte Puertas ( Université Laval )

There are currently ~1500 known supernova remnants (SNRs) spread across a dozen galaxies where most of them have been identified optically. These objects chemically enrich their host and influence future generations of stars. Distinguishing SNRs from HII regions is not straightforward. Most authors consider an emission lines ratio [SII]/Hα > 0.4 for this. Recently it has been proposed to study the velocity structure to differentiate them as well, since SNRs show a larger velocity broadening than HII regions. In this work we combine these two prescriptions, i.e. the [SII]/Hα value and the velocity structure, for a sample of SNRs in two galaxies of the Local Group, NGC6822 and M33. Both galaxies have been observed with the imaging Fourier transform spectrometer SITELLE, developed in Québec (U. Laval and ABB) and installed at the Canada-France-Hawaii Telescope, as part of the SIGNALS survey. Our observations offer a minimum spectral resolution R = 3000. Bearing in mind also the large field of view (11'×11'), high spatial resolution (0.32''/pixel, seeing limited), and the spectral ranges of SITELLE, this work have allowed us to perform a spatially resolved study of all SNR candidates in these two galaxies taking into account these criteria for the first time. From our study we discard some published SNR candidates in NGC6822 and M33. This is the first work in a series dedicated to the detection of all SNRs in the SIGNALS sample.