SIMBAD references

We have examined 18 known supernova remnants for evidence of the 22.235-GHz water maser spectral line, using the 20-m telescope at the Onsala observatory in Sweden. No evidence of such emission was discovered above the background noise in any of the observations. We have developed a radiative transfer water maser model for the shocked regions of supernova remnants in order to determine why this emission was not detected. The model indicates an insignificant amount of 22.235-GHz gain; the gain lengths are far too short to allow the formation of detectable water masers from these objects. We predict that only in unusual environments can 22-GHz water masers be detected around supernova remnants.