Data Analysis Markarian 421 – Crab Nebula – Crab Nebula –  2 dim plots : false source analysis  Miss-pointing study  Light Curves Data:

Applied Cuts (David’s Talk) 0.12 < LENGTH < < WIDTH < < DIST < 1.3 SIZE > 3000 ( photons) Calculate significance: Li&Ma (1983) formula #17 ALPHA(max) = 10 degrees

False source analysis Calculate once source independent parameters: LENGTH, WIDTH, SIZE, etc For each assumed source position calculate source dependent parameters: DIST, ALPHA The movement of the sky (derotation) The same procedure for ON and OFF

2 dim sky plot Camera coordinatesSky coordinates

2 dim sky plot (N ex) Camera coordinates Sky coordinates

Why is the spot not very narrow? Center of the camera is not the center of the rotation? Divide the ON sample in several sub-samples No derotation Use the whole OFF sample to calculate significance

Tracking / Miss-pointing

Estimation of the source position in each of the sub-samples Several criteria: Significance Number of excess events Alpha plot: signal and background shape Alpha plots of the nearby positions

Estimated source positions

First light curve Markarian 421

Fine binning: 25 samples Normal spotAbnormal spot (1 run)

Closer look to this sub-sample 2 minutes, 1 Run, no reports in the runbook First 5633 eventsLast 5633 events

Following the miss-pointing

Mrk421: 2 nd ON sample Derotation around the center of the camera Displacement from the center of around 0.3 deg Roundish spot

Second light curve

Zenith and azimuth angle

Crab: 27th January 2004

Crab: 14 th - 15 th February 2004

Conclusion / outlook All three samples: clear detection Weak sources (even Crab!) still difficult to analyze. Possible reasons: miss-pointing unstable movement many “dead” pixels

Mrk 421 OFF

ASYMMETRY

Asymmetry: MC photons 73% 27%

Asymmetry: MC protons 40% 60%

Asymmetry: Mrk 421 ON 44% 56%

Asymmetry: Mrk 421 OFF 39% 61%

Asymmetry: Crab ON 40% 60%

Asymmetry: Crab OFF 38% 62%