You will see my analysis of supernova named Cassiopea A, using js9.
We have done an energy spectrum using the previous software and the image obtained contain peaks and every peak correspons to a single chemical element.
We obtained these chemical elements using the website of Dr Kolena.
Enclosed below you can see the image of the x-ray spectrum from Chandra space telescope we a mesured area at 1800 electron-volt produced by Silicium XIII
Silicium XIII means silicium ionized twelve times, that is silicium wethe twelve electrons removed. As neutral silicium has 14 electrons, this means trhat only two electrons remains in Silicium XIII and they produced the emission line
And finaly use imagej to measure the peaks in the image