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First Analysis Results of the Crab Nebula and Mrk421

First Analysis Results of the Crab Nebula and Mrk421. M. López Moya U.C.M. Analysis chain Mrk421 Camera rotation study Light Curve Crab Nebula. Analysis chain (1). Calibration and Pedestal substraction Used the standard calibration classes

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First Analysis Results of the Crab Nebula and Mrk421

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  1. First Analysis Results of the Crab Nebula and Mrk421 M. López Moya U.C.M. • Analysis chain • Mrk421 • Camera rotation study • Light Curve • Crab Nebula Udine bootcamp

  2. Analysis chain (1) • Calibration and Pedestal substraction • Used the standard calibration classes • P,C runs selected by hand: needed a method to look autmotically for the closer P,C runs to a given D run. • Pedestal runs seem to work fine, but many problems using calibration runs: many pixels look after calibration. Udine bootcamp

  3. Analysis chain (2) • Image cleaning • Lvl1 = 3.0, Lvl2 = 2.5 (one ring) • We started to investigate the dependence of cleaning cuts, but no conclusive results yet: just that 5:3 seems to work better for the Crab. • Forseen insland analysis and moun rings rejection, specially to analysis at low energies. Udine bootcamp

  4. Analysis chain (3) • Signal Extraction • We use: MExtractSignal2 • Hillas Paramter cuts • for the time being, only use SIZE, LENGTH, WIDTH & DIST. • we used static cuts: no dependence with zenith angle took into accout Udine bootcamp

  5. Analysis chain (4) • Getting the telescope pointing postion • Poiting position stored only in CC reports at a fixed frecuency • For having it in an event by event base, we extrapolated it using the arrival time of the event. Udine bootcamp

  6. Analysis of Mkn 421 Udine bootcamp

  7. Mrk 421 (1) • Data Set 15 Feb.2004 Udine bootcamp

  8. Mrk 421 (2) • Hillas cuts: SIZE > 2000 0.1 < LENGTH < 0.3 0.05 < WIDTH < 0.12 0.6 < DIST < 1.4 Udine bootcamp

  9. Mrk 421 (3) • Correcting the mispointing: The False Source Plot • We consider as source position, the position at the maximum in the 2D alpha plot • Fitting the Alpha Plot • Signal region < 10 • Backg. region: between 30- 90 • Fit the Backg. region to a 2nd order polinomial. From it extrapolate the bg. in the signal region • The significance is calculated according to LiMa Udine bootcamp

  10. ON data OFF data Udine bootcamp

  11. Alpha plot at Src position Udine bootcamp

  12. Alpha plot for SIZE > 3000 Udine bootcamp

  13. Mrk 421 (4) • We get nearly 20 , but a relative broad alpha plot. • The significance is high enough to split this day into subsamples. This allows: • Study camera rotation: is really the rotation uniform? • Get the ligth curve for that day Udine bootcamp

  14. Mrk 421 : Camera rotation (1) • We divide the whole night (1:45 h) into 10 subsamples • Now, we don´t apply the camera rotation algorithm. Udine bootcamp

  15. Mrk 421: Camera rotation (2) Udine bootcamp

  16. Udine bootcamp

  17. Mrk 421: Light curve (1) • For each of the subsamples, we get the source position and it corresponding alpha plot. • From each alpha plot, we get the number of excess events, that we plot vs. Time, obtaining the light curve for that night. Udine bootcamp

  18. Mrk 421: Light curve (2) Udine bootcamp

  19. Mrk 421: Light curve (3) Udine bootcamp

  20. Mrk 421: Light curve (3) • BUT, this light curve depends strongly on: • the binning criterium (binning in RunNumber, RunTime,...) • the hillas cuts • Also we check the time stamp Udine bootcamp

  21. Mrk 421: Checking timestamp (1) Udine bootcamp

  22. Mrk 421: Checking timestamp (2) Udine bootcamp

  23. Analysis of the Crab Nebula Udine bootcamp

  24. Crab Nebula (1) • Data Set 15 Feb.2004 Udine bootcamp

  25. Alpa plot Udine bootcamp

  26. Conclusions • So far, only analyzed the night: 15 Feb 2004. • For Mrk 421 seems easy to get a nice signal, without using a detailed calibration or cut optimization. We get around 20 . • According the light curve, although we see some variation, it is difficult for the time being to relay on it. • Mrk 421 also quite useful to understand telescope behaviour. • For the Crab the situation is more complex. Seems that different cuts should be used. We get only about 6 . Udine bootcamp

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