http://commons.wikimedia.org/wiki/File:Fluorescent_lighting_spectrum_peaks_labelled.png

Peak number Wavelength of peak (nm) Species producing peak Actual line location (nm) 1 405.4 mercury 404.656 2 436.6 mercury 435.833 3 487.7 terbium from Tb3+ ~485 to 490 4 542.4 terbium from Tb3+ ~543 to 544 5 546.5 mercury 546.074 6 577.7 likely terbium from Tb3+ or mercury 576.960 for Hg or ~578 for Tb 7 580.2 mercury or terbium from Tb3+ 579.066 for Hg or ~580 for Tb 8 584.0 possibly terbium from Tb3+ or europium in Eu+3:Y2O3 ~580 9 587.6 likely europium in Eu+3:Y2O3 ~587 10 593.4 likely europium in Eu+3:Y2O3 ~593 11 599.7 likely europium in Eu+3:Y2O3 ~598 12 611.6 europium in Eu+3:Y2O3 ~611 13 625.7 likely terbium from Tb3+ ~625 14 631.1 likely europium in Eu+3:Y2O3 ~630 15 650.8 likely europium in Eu+3:Y2O3 ~650 16 662.6 likely europium in Eu+3:Y2O3 ~661 17 687.7 likely europium in Eu+3:Y2O3 ~687-688 18 693.7 likely europium in Eu+3:Y2O3 ~693 19 707 and 709 likely europium in Eu+3:Y2O3 ~707 and ~709 20 712.3 likely europium in Eu+3:Y2O3 ~712 21 760.0 likely argon 758.9315 or 763.5106 (??) 22 811.0 likely argon 811.531

Jeff, what are the peaks we're seeing? And how are they calculated?