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We present results of a search for supernova remnants (SNRs) in archivalChandra images of M33. We have identified X-ray SNRs by comparing the list ofChandra, X-ray sources in M33 with tabulations of SNR candidates identifiedfrom (1) elevated [S II]/Halpha ratios in the optical, and (2) radio spectralindices. Of the 98 optically known SNRs in M33, 22 have been detected at >3-sigma level in the soft band (0.35-1.1 keV). At least four of these SNRcandidates are spatially extended based on a comparison of the data tosimulated images of point sources. Aside from the optically matching SNRs, wehave found one soft X-ray source in M33 which exhibits no optical emission andis coincident with a known radio source. The radio spectral index of thissource is consistent with particle acceleration in shocks, leading us tosuggest that it is a non-radiative SNR. We have also found new opticalcounterparts to two soft X-ray SNRs in M33. Pending confirmation from opticalspectroscopy, the identification of these two optical counterparts increasesthe total number of known optically emitting SNRs in M33 to 100. This bringsthe total number of identified SNRs with X-ray counterparts, including thoseexclusively detected by the XMM-Newton survey of M33, to 37 SNRs. We find thatwhile there are a similar number of confirmed X-ray SNRs in M33 and the LMCwith X-ray luminosities in excess of 1e35 ergs/s, nearly 40% of the LMC SNRsare brighter than 1e36 ergs/s, while only 13% of the M33 sample exceed thisluminosity. The differences in luminosity distributions cannot be fullyexplained by uncertainty in spectral model parameters, and is not fullyaccounted for by abundance differences between the galaxies (abridged).Comment: 33 pages, 11 figures, 3 tables; accepted for publication in the  Astronomical Journa

Revealing the Supernova Remnant Population of M33 withChandra