This is a fit to the full set of CHICOS data (275 showers). After a cut on angle (theta<1), there are 145 showers in the energy range covered by simulations (LogE>18.4).
The method being used here is:
- Call the flux x E^3 at each point C_data = N(logE) E^3/(.46E A(E) T)
- Fit the result to a line: log(C_data) = log(C2)-(gamma-3)log(E)
- This gives an estimated flux J2 = C2 E^-gamma
- J2 can be used to estimate the expected number of data points in each bin:
N2 = Int(.46E*A(E0)R(E,E0)J(E0))dE0
- Turn N2 into F*E^3: C'= N2 E^3/(.46E A(E) T)
- Re-estimate J as J_Measured = (C_data/C')C2 E^-gamma
Code used:
- spectrum.C: Reads in Chiquita shower file and
makes histograms of data and flux*E^3 for each energy shift.
- iteratefit.C: Turns flux histograms into
Log(Flux*E^3) so they can be fit with a line.
- fitfn.C: Takes flux and returns number-per-bin.
- newflux.C: Takes N-per-bin and makes histogram of
flux*E^3.
- ratios.C: Gets ratio of C_data to C' and
multiplies the points from the best fit line by this ratio.
- getlog2.C: Turns final histograms into
Log(Flux*E^3) so they can be fit with a line. (Not currently used.)
- error.C: Gets the max and min errors.
- drawspec.C: Draws final result on top of
other data. (Not currently used.)
Root files:
- hists.root: Contains R(E,E0) and A(E0)
CHICOS data, and equivalent histograms with the energy shifted by +/- 20%:
The points in the following histogram are C_data(logE):
Fit to the data:
The points above are used to estimate the equivalent number-per-bin:
This histogram is fed back into the same function that was used to estimate the Flux*E^3 from the data. The points on this histogram are C'(E) in the expressions at the top of the page.
The ratio between each pair of points in the above histogram (C_fit=C'):
The estimated flux from the best-fit line (C_2 E^-g) times the ratio of C_data/C'
CHICOS data and error band:
Aperture from simulations:
