Spectrum Contrast - Thermal vs. Cosmic Rays

These two spectra show the difference between thermal and synchrotron emission. In the thermal spectrum (top), many narrow features, or lines, are apparent. These lines represent transitions between two distinct energy states in a particular atom. It is possible to identify what element is responsible for the emission from the energy of the line. In contrast, the spectrum from synchrotron emission does not show these narrow features, but appears as a straight line. There is more flux at lower energies.

(http://heasarc.gsfc.nasa.gov/docs/objects/snrs/casa_spectra.html)

X-ray spectrum of Cas-A (http://heasarc.gsfc.nasa.gov/docs/objects/snrs/casa_spectra.html)

(http://heasarc.gsfc.nasa.gov/docs/objects/snrs/sn1006_spectra.html)

X-ray spectrum of SN 1006 (http://heasarc.gsfc.nasa.gov/docs/objects/snrs/sn1006_spectra.html)