Luminosity (0.1−100 GeV) of several Fermi-LAT observed SNRs plotted against their diameter squared. Blue diamonds are the SNRs interacting with molecular clouds, while orange circles are young SNRs. The SNR Puppis A, a middle-aged SNR that is not interacting with a molecular cloud, is represented by the green triangle. Black stars correspond to the SNR G150.3+4.5 using a distance of 0.7 and 4.5 kpc, respectively. The figure is reproduced from Thompson et al. (2012) with the addition of G150.3+4.5.