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H is a tracer of thermal emission.
A comparison of the two surveys will give insights into the distribution of the different mechanisms. Because the radio emission is not affected by dust extinction, the MOST images contain many extragalactic objects, in particular background galaxies which are seen as unresolved sources. These radio galaxies will not be seen in H . The vast majority of the H emission will be from our Galaxy, in the form of extended filaments and clouds. Supernova remnants also characteristically have filamentary structure, in this case produced by the nonthermal synchrotron process.