Hadronic model H4 of the gamma-ray spectrum of W44 that is superimposed with the gamma-ray data of Fig. 1 (in blue and cyan colors). We find an index p₁ = 3.2 ± 0.1 with a low-energy cut-off at GeV. This model is characterized by B = 145 μG and n = 300 cm^-3. The yellow curve shows the neutral pion emission from the accelerated proton distribution discussed in the text. The dashed black curve show the electron contribution by bremsstrahlung (dashed) emissions; the IC contribution is negligible. The red curve shows the total gamma-ray emission from pion-decay and bremsstrahlung.