Fig9_5 Radio-frequency spectrum of the Orion Nebula

Fig9_5 Radio-frequency spectrum of the Orion Nebula

Fig. 9.5 . Radio-frequency spectrum of the Orion Nebula, also designated as M 42, showing the hydrogen, H, and helium, He, recombination lines from the a (m-n=1) and b (m-n=2) transitions at high quantum numbers n = 109 and n = 137. The hydrogen lines are more intense than the helium or carbon ones because of the greater abundance of hydrogen. (Adapted from K.R. Lang, Astrophysical Formulae, Heidelberg: Springer Verlag 1979.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University