Hello again,
You haven't been counting very long, have you ?
There is some similarity with e.g. the plot
here
I hope your 'peaks' are only the ones at 1173 and 1332 keV ? The others are hard to distinguish and that means fitting will be hard too.
The general recipe is:
Form an expression for the assumed counting rate N(x) in a certain energy range, e.g. for two gaussian peaks on a quadratic background:$$N = ax^2 + bx + c \quad
+ C_1 \exp\left (- {(E_1-x)^2\over 2 \sigma_1^2}\right ) \quad +
C_2 \exp\left (- {(E_2-x)^2\over 2 \sigma_2^2}\right ) $$ and minimize ##\sum \Bigl (n_{observed}(x) - N_{expected}(x)\Bigr )^2## by varying the fit parameters ##(a,b,c,C_1, E_1,\sigma_1,C_2, E_2,\sigma_2)##
Figure below shows a half-hearted attempt with C1 =560, C2 = 480
but my hunch is you have software tools at your disposal that do this a whole lot better ...
And the binning together as
@gleem proposes reduces the noise considerably
##\ ##