<source name="radial_source">
       <spectrum escale="MeV">
         <SpectrumClass name="RadialSource"
           params="flux=1e-03, profileFile=radial_profile.dat, specFile=b-bbar_100GeV.dat, ra=74.9344, dec=27.6906"/>
         <use_spectrum frame="galaxy"/>
       </spectrum>
     </source>