set terminal postscript eps color enhanced font "Helvetica,16pt" size 8.6cm,6cm
set output "spectrum_hgarsun.eps"

set key
# set tics scale 2
set xr [350:1000]
set xl "{/Symbol l} [nm]" offset 0,0.3
set xtics 100 
set yr [10:40000]
set yl "Relative intensity" offset 0,0
set log y 10
set format y "10^{%T}"

plot "spectrum_hgarsun.dat" using 1:4 w l lw 2 lt 1 lc 1 ti "Sun", \
"" using 1:3 w l lw 2 lt 1 lc 3 ti "Arc", \
"" using 1:2 w l lw 2 lt 1 lc -1 ti "Hg"