# M82 spectrum

## Results

- The spectrum map is defined by index = log(Map_140/Map_240)/alog(140.0/240.0). We can clearly see a change in the spectral index in the source. This is confirmed by the correlation plot which shows the values in the pixel of the 240 GHz map as a function of the value of the corresponding 140GHz map.

## Possible interpretation

- The slopes of 0.6 and 1.25 correspond respectively to spectral index of +1 and -0.4. We might understand it if we consider that the contribution of the emission of M82 is due to dust and free-free. The center of M82 is therefore dominated by free-free emission and the outskirt is dominated by dust.