1. Event by Event Energy Estimation Algorithm and Determination of Spectra (Update) Branden T. Allen, MILAGRO Colaboration Meeting, May 2006

2. Old Energy Estimation Algorithm From the Gamma MC Simulations a relation between MC Energy and  f, r f, N is determined. Division into i-core bins and j-zenith angle bins allows a relation for E f vs. N to be determined for the i-th and j-th bin. Application of Standard Cuts E f >0, N AS >50, N fit >20, r f <100m,  <2.1 º

3. Characteristics of the Old Energy Estimation Method

4. Old Energy Resolution

5. Corrected Resolution (Representative)

6. New Banana Plot

7. Determination of Spectra Determination of spectra through chi squared minimization. Number of excess events (N i ) and significances (  i ) determined for the i-th energy bin. Number of predicted excesses for an input spectrum (n i ) may be calculated as a function of I o and .

8. Determining Spectra (Resolution Function Properties) (Review) f(E,E f,  f ) is the probability that a MC Energy between E and E+dE, will be assigned and fit energy between E f and E f +dE f., in the zenith angle range [  f,  f +d  f ]. Probability that an MC event will be assigned to the i-th fit energy bin normalized to 1.

9. Determining Spectra Determination of the expected events in each energy bin, assuming power law spectrum. MINUIT minimization package utilized, for determination of the spectra.

10. Old Crab Measurement

11. Improvements to be made and future plans (December List) Dead Tubes, and occasionally dead patches… Is there a significant effect on energy resolution and measurments of spectra? Extension of the crab spectrum beyond 40TeV (High E MC Generated to this end) Bin size optimization for different energy bins. Spectra for MRK421 (Is it Possible?) and the Cygnus Hot Spot (In progress). Use Andy‘s Weights….. (Currently In progress)