Interstellar Gas toward the Magellanic Supernova Remnants

We present new CO observations toward 25 supernova remnants (SNRs) residing with the Large Magellanic Cloud, including the TeV gamma-ray sources N132D and 30 Doradus C. Our observations revealed that similar to 90% of the SNRs were detected by (CO)-C-12(J = 1-0) line emission with a 3 sigma level or higher. At least ten of them were shown to have CO clouds that have a good spatial correspondence with thermal /non-thermal X-rays; this indicates that shock-cloud interactions may have occurred. The molecular gases associated with N132D showed a high intensity ratio of (CO)-C-12 J = 3-2 /1-0 > 0 : 8, indicates that shock-heating occurred. We also found five molecular clouds and three Hi clouds associated with 30 Doradus C, which showed either complimentary or similar distributions to the non-thermal X-ray filaments in a 10 pc scale. The interstellar proton density of 30 Doradus C was estimated to be similar to 60 cm(-3), which corresponded to the total energy of the cosmic-ray protons being at least similar to 1.2 x 10(50) erg.