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During an [O III] survey for planetary nebulae, we identified a region inSagittarius containing several candidate Supernova Remnants and obtained deepoptical narrow-band images and spectra to explore their nature. The images ofthe unstudied area have been obtained in the light of Halpha+[N II], [S II] and[O III]. The resulting mosaic covers an area of 1.4x1.0 deg^2 where filamentaryand diffuse emission was discovered, suggesting the existence of more than onesupernova remnants (SNRs) in the area. Deep long slit spectra were also takenof eight different regions. Both the flux calibrated images and the spectrashow that the emission from the filamentary structures originates fromshock-heated gas, while the photo-ionization mechanism is responsible for thediffuse emission. Part of the optical emission is found to be correlated withthe radio at 4850 MHz suggesting their association, while the WISE infraredemission found in the area at 12 and 22 micron marginally correlates with theoptical. The presence of the [O III] emission line in one of the candidate SNRssuggests shock velocities into the interstellar "clouds" between 120 and 200km/s, while the absence in the other indicates slower shock velocities. For allcandidate remnants the [S II] 6716/6731 ratio indicates electron densitiesbelow 240 cm^{-3}, while the Halpha emission has been measured to be between0.6 to 41x10^{-17} erg/s/cm^2/arcsec^2. The existence of eight pulsars within1.5deg away from the center of the candidate SNRs also supports the scenario ofmany SNRs in the area as well as that the detected optical emission could bepart of a number of supernovae explosions.

Discovery of optical candidate supernova remnants in Sagittarius