Analysis chain for MAGIC Telescope data Daniel Mazin and Nadia Tonello Max-Planck-Institut für Physik München D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004

D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Technique ~ 10 km ~ 1 o Cherenkov light ~ 120 m Particle shower Atmosphere Cherenkov light Image of particle shower in telescope camera: Imaging Air Cherenkov Telescope

Calibration MAGIC Camera D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Calibration runs: same number of photons in all PMs Calibration methods: Ffactor method (relative calibration) Muons (absolute calibration) Blind-pixel method …to be installed

Charge extraction D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Extract signal from ADC data: signal digitized every 3.3 ns pedestal subtraction sum N-ADC slices N=large: collect charge in tails N=small: reduce NightSkyBackground contribution typical value: N=4 Pulse shape after pedestal subtraction

Calibration MAGIC Camera D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Calibration runs: Output of PMs not uniform After calibration: All PMs show the same photon density Relative pixel to pixel calibration

Q Mean charge for pixel from a calibration run  2 Q  variance from the charge distributions of the pixel F 2 correction for intrinsic noise of the photomultiplier Calibration D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Mean number of photoelectrons N phel = (Q 2 /  2 Q ) F 2 where F 2 = (measured) absolute calibration in number of photoelectrons

Image cleaning D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Calibrated chargeArrival time Signal/NoiseShower image

Hillas Parameters D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 gamma showerhadron shower (background) muon shower Shower reconstruction and background rejection based on image shape analysis Hillas parameters: LENGTH, WIDTH, DISTANCE, SIZE, ALPHA, …

 -hadron separation D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 MC-  Black: data MC-hadrons MC-  Black: data MC-hadrons PRELIMINARY  -hadron separation by using cuts in: LENGTH, WIDTH, DISTANCE, etc Since all these parameters are not independent, we use Dynamical cuts LENGTH WIDTH Remark: cuts are optimized using ON and OFF data. MC data are not used for optimization due to ongoing tuning of MC

 -hadron separation D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 SuperCuts hadrons gammas SIZE WIDTH Current analysis

 -hadron separation D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Mean Scaled Hillas For each SIZE bin Mean value of LENGTH is calculated (red curve). Black curves – optimized cuts on LENGTH.

 -hadron separation D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Mean Scaled Hillas For each SIZE bin Mean value of WIDTH is calculated (red curve). Black curves – optimized cuts on WIDTH.

Alpha plot D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004

Source Position D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 First step: pointing and tracking precision Star guider (online correction, being commissioned) Use anode currents to determine star positions (offline) For determination of the source dependant parameters: SOURCE POSITION is needed Preliminary results by using anode currents: Position with a statistical error ~0.01  possible to detect stars until 8 th magnitude in the inner pixels updating every 10 sec Second step: determine source position (known coordinates) Triangulation Crab Nebula Mrk 421H C279

False Source Method D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 If the source position unknown: 1.For each position in FoV the source dependant parameters are calculated 2.The same for the OFF data 3.For all positions in FoV the alpha plot is produced and Nexcess / significance are calculated ~5min of Mrk421 data

OUTLOOK D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 Other analysis techniques: Further optimization of gamma-hadron separation using Hillas parameters: Random Forest (is used) Neural Net (ready to be used) Fit the complete camera event information: Model Analysis (being development) Lightcurve (gamma-flux as a function of time) Energy spectrum Further analysis steps:

OUTLOOK D.Mazin, N.Tonello MPI for Physics, Munich ISCRA 14 th Course Erice, 2 nd -13 th July 2004 NEXT TALK: MAGIC first results presented by Ester Aliu