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Status on the cross check analysis for the e + +e - flux estimation

Status on the cross check analysis for the e + +e - flux estimation. Villi Scalzotto – Luigi Cossio – Michele Palatiello Udine, MAGIC Collaboration Meeting 2012 – June,10 th -16 th. Quick introduction Description of the method Data set informations CRAB Test of the method

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Status on the cross check analysis for the e + +e - flux estimation

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  1. Status on the cross check analysis for the e++e-flux estimation Villi Scalzotto – Luigi Cossio – Michele Palatiello Udine, MAGIC Collaboration Meeting 2012 – June,10th-16th

  2. Quick introduction • Description of the method • Data set informations • CRAB Test of the method • Electron Flux estimation • Discussion Outline This is the status of a CROSS CHECK analysis of DANIELA BORLA TRIDON's results on the e+e- spectrum

  3. CR-Electrons • At TeVenergies, CR-electronscarryinformationsaboutnearbysources, due to energylosses via synchrotronradiation and IC-scattering. • Lifetime(propagationdistance) islimited • (105lyr 1kpc) • Spectrumisisotropic and steeperthanhadronicCRs(~ E-3.3 vs E-2.7) • Direct measurementsat HE isthendifficult, but a chance for Cherenkovtelescope: • - largercoll. area thansatellites(~ 105 m2) • - sufficient energy resol. to resolve the spectrum, such to discriminate amongdifferentmodels

  4. Origin • Electrons lose energyby: • Ionization • Synchrotron • Inverse Compton • Bremsstrahlung • Possiblecontributionsto HE electronsflux: • Secondaryelectronsgenerated in CR interactions with ISM • Supernova explosion (sharpcutoff in the spectrum) • Distantsourcesuniformlydistributed • Pulsars • Dark matter

  5. MAGIC & THIS PHYSICAL CASE INTENT: use MAGIC to support or not ATIC/FERMI/HESS result PRO: No dedicated time AGAINST: Lower sensitivity Large MCProtons simulation needed to match MCProtons to RealData MAGIC Results by other experiments Villi Scalzotto FERMI ATIC HESS

  6. All the real data contain electrons (both ON and OFF!) The normalization of the Alpha plot allows to obtain the same amount of electrons in ON and in OFF: HOW TO COUNT ELECTRONS? GAMMAS and ELECTRONS morphologically equivalent for MAGIC BUT ELECTRONS are DIFFUSE ALPHA parameter not useful! electrons USE OF HADRONNESS AS SIGNAL PLOT

  7. THE METHOD Theta2 Hadronness STD ANALYSIS 0 0.3 0 1 • "ON" Data (with gamma rays from a pointlike source) • Non leptonic cosmic rays (p, He, ecc.) renorm. • "OFF" Data (with diffuse Electrons (and diffuse gammas) renormalized Theta2 Hadronness HADPHA METHOD Hadpha stands for the Hadronness parameter used as "Alpha" for the signal plot 0 0.3 0 1 • MC Protons simulation (+He + diffuse gammas) • Real Data from a dark patch (thus diffuse electrons+ non leptonic cosmic rays)

  8. THE HADPHA METHOD ELECTRONS are mostly gammalike HADRONS are mostly hadronlike …GAMMAS…are mostly gammalike! ? Hadronness: our new “Alpha” “ON” : MAGIC OFF (with electrons and no gamma contamination) “OFF”: SIMULATION OF THE BACKGROUND (no electrons in the background) No ALPHA/THETA2 plot As signal plot NO ALPHA/THETA2 cut! Hadronness plot used to find signal!

  9. DATASET Datasets needed (all in STEREO):Real DataCRAB ON data (7.5h)OFF data (14h)SimulationMC electrons (~4e5 after stereo trigger)MC pointlike gammas (~1.6e5 after stereo trigger)MC protons (~1.4e6 after stereo trigger)In the future:Helium, diffuse gammas, more and more protons…mostly given by Daniela Borla Tridon,extension thanks to Luigi Cossio and Michele Palatiello

  10. REAL "OFF" DATA BL Lac 3c454 1FGL J2347.3+0710 RA 22h00m39.3723s DEC +42d02m08.495s • Galactic long: 92.58 lat -10.44 • z=0,068 • 15-17/6_2010 • Zdmin=26Zdmax=31 • Data selection: bad rate (manually checked) and cloudiness Total effective time after cuts: 2.12 h RA 22h51m34.7s DEC +18d48m40s • Galactic long: 87.35 lat -35.65 • z =1.75 • 6-8-10-11/12_2009 • Zdmin=15Zdmax=30 • Data selection: bad rate (manually checked) and cloudiness Total effective time after cuts: 2.93 h TOTAL ~ 14h RA 23h47m19.9s DEC +07d10m26s • Galactic long: 96.29 lat: -52.35 • z =N/A • 6-10-11-13-31/10_2010, 01-25 /11_2010 • Zdmin=21.5Zdmax=30 • Data selection: bad rate (manually checked) and cloudiness Total effective time after cuts: 8.84h

  11. REAL "OFF" DATA Zenith angle distributions of the dataset

  12. CRAB DATA CRAB ON STEREO DATA SAMPLE: • RA 05h34m32.0s DEC +22d00m52s • Gal long 184.557593 lat -5.784197 • 8-9-10-11-12-14/11_2010 • Zdmin= 7Zdmax=19 • Data selection: bad rate (manually checked) and cloudiness Total effective time after cuts: 7,57

  13. MC SIMULATION Simulated events (@ 2012): ELECTRONS Zenith 5-35 degrees 70 GeV – 7 TeV (and 30 TeV) ViewCone: 4.5 deg, PowerLaw: -2 # = O(8.107) PROTONS Zenith ~ 0-38 gradi Various populations: from (30,70,70) GeV to (30,20,30) TeV ViewCone: 5/6 deg, PowerLaw: -1.78/-2 # = O(2.109) Events surviving the triggering of the stereo system: Electrons: O(4.105) (~0.4%) evts Protons: O(1.4.106) (~0.07%) evts Cleaning M1:6/3 time M2: 9/4.5 time

  14. MC SIMULATION In addition: HELIUM Zenith 8-38 deg 70 GeV - 20 TeV ViewCone: 5/6 deg, PowerLaw: -2 # = O(4.108)  Post Trigger = 1.1.105 (0.03%) DIFFUSE GAMMAS Zenith 5-30 deg 10 GeV - 30 TeV ViewCone: 0 deg, PowerLaw: -1.6 # = O(3.107)  Post Trigger = 1.8.106 (6%) POINTLIKE GAMMAS Zenith 5-35 deg 10 GeV - 30 TeV ViewCone: 1.5 deg, PowerLaw: -1.6 # = O(2.106)  Post Trigger = 1.6.105 (8%) NOT YET USED FOR THIS ANALYSIS

  15. USED RF matrix RF Crab Test: RF Electrons study: Train: BKG: BL Lac 0.56h + 3c454 0.51h MC: pointlike gammas Train: BKG: BL Lac 2.12h + 3c454 2.93h MC: electrons (Daniela + Luigi) Cuts NTree: 100 RF.trainRatio: 0.95 Leakage1>0.15 NumIslands>1 Energy Estimation: STD LUTS by MC RFtest sample PARAMETERS: MaxHeight (stereo reconstructed) Size (M1 and M2) Length (M1 & M2) Impact par. (M1 & M2) TimeGrad (M1 & M2) (MHillasTimeFit_*.fP1Grad) MaxHeight (M1 & M2) Width (M1 & M2)

  16. Leakage{1,2} < 0.2 • Dist{1,2} <300 mm • NumIslands{1,2}<2 • Size1>100-150 • Size2>200-250 • 10-12<Impact{1,2}[m]<250-300 • MuonRingCenterDist<20 Quality cuts These cuts have been applied at the electronflux level in order to obtain a better match between MCProtons and RealData

  17. PARAMETER DISTRIBUTIONS after the quality cuts Comparison between Real Data and MC protons after the quality cuts. The MC sample is corrected considering the different power law.

  18. PARAMETER DISTRIBUTIONS after the quality cuts Parameters as function of the energy. In case of M2, the agreement is quite good.

  19. PARAMETER DISTRIBUTIONS after the quality cuts Case of M1.

  20. PARAMETER DISTRIBUTIONS after the quality cuts Quite ok. Perhaps there is a small mismatch for the distributions of L,W,M3Long.

  21. CRAB DATA Crab Nebula test To test the performances of the Hadpha Method we use it to estimate a flux by a standard gamma source (Crab). The method will be obviously less performing than the usual Theta2 Method. But the spectrum of a strong gamma source should be obtained. Standard RF, hadronness plot as significance plot

  22. CRAB TEST Theta VS Hadpha Theta2 Method • EffArea after cuts is lower for Theta Method because it includes the hadronness plot. • But remember the sensitivity of the Hadpha method is lower! Hadpha Method

  23. CRAB TEST Theta VS Hadpha Theta2 Method Good ON/OFF match! Hadpha Method We are using Real Data both for ON and OFF. We do expect this match is not that good in the electron case! 0.4-0.8 seems a good normalization range

  24. CRAB TEST Theta VS Hadpha Theta2 Method The points are consistent within errors. But there is still a slight underestimation to be understood. Hadpha Method

  25. HADPHA METHOD SENSITIVITY Theta2 Method As expected, the sensitivity (in Crab units for 50hrs) is worse (~factor 4 for differential sensitivity). The lowest points for Hadpha are not trustable (see later). Hadpha Method

  26. Theta2 Method

  27. Hadpha Method In this method it's very peculiar the selection of the normalization region

  28. 11<Zd<30 // 20<Zd<30 • Azimuth bins: 1 / 9 • Energy Bins: 20 / 25 / 30 • Hadpha Efficency: 0.55 – 0.75 • Normalization region: [0.4/0.45 --- 0.7/0.85] Electronflux options Different flux have been extracted by varying some options in a reasonable range

  29. Different Hadpha normalization region possible… Discrepancy at the highest values Perhaps it's enough to apply a quality cut

  30. Discrepancies at the lowest energy values (as in Daniela's work). Due to mismatch btw simulation and real data. The matching improves with the energy.

  31. Signal persists at higher energies, above 1 TeV, but these number of excesses would give huge values in the spectrum. Lack of statistic? To investigate.

  32. ??

  33. e++e- DIFFERENTIAL SPECTRUM • E3dN/dE spectra are highly sensitive to the variation of some options in the input card • Main variations due to Zd range, Hadpha Efficiency and the normalization region • We superimpose the different result. We divided it into 2 samples, with lower and higher Hadpha Efficiency HadEff = 0.7-0.8 HadEff = 0.55-06

  34. e++e- E3Spectrum FERMI HESS MAGIC CROSS CHECK

  35. e++e- E3Spectrum HadEff = 0.7-0.8 HadEff = 0.55-06

  36. Public result Shown at ICRC'11 ICRC proceeding

  37. Technical considerations • There is a mismatch at high hadronness values to be better understood (in disagreement with Daniela's result) - We used the reweighting • The method is sensitive to the Zd selection and the normalization region • Crab Test with diffused electrons to better understand the behaviour of the ViewAngleCone • Behaviour at high energies? Why do the values seems to increase? • E3dE/dN distribution is highly amplifying the fluctuations. It's a very precise work to deal with.. • The fluctuations obtained by varying the electron flux options could give an estimation of our systematics due to the analysis

  38. Conclusions • Results are consisent with Daniela's work, but the E3dN/dE spectrum looks a bit higher. • Range 150<E<1000 GeV. Problems at higher energies. • We have reported an overlap of spectra. No PowerLaw estimated yet. • We cannot exclude the presence of a flux higher than expected and measured by Fermi. • Analysis is finally working (in the past several problems with this crosscheck!) • Need to fine tune some disagreement (large hadronness mismatch and high energy values). Larger MC production could help.

  39. BACKUPs

  40. Consistency considerations in the mono case: • Electrons are diffuse: • we need to integrate over the solid angle • (we assume an “effective” FOV • of 0.4deg X 0.4deg = 1.5*10-4 sr) • At 500 GeV: • CRAB = 2 10-13cm-2 s-1 GeV-1 • ELECT (Fermi) = 114/E3(GeV) m-2 s-1 GeV-1 sr-1 • = 9 10-11 * 1.5 10-4cm-2 s-1 GeV-1 sr-1 • = 1.35 10-14 cm-2 s-1 GeV-1 • Elect.Flux ~ 7% Crab! • Observation time: 50*(10/7)2 = 100 h

  41. MC Protons M1 vs M2

  42. MC Protons M1 vs M2

  43. Real Data M1 vs M2

  44. Real Data M1 vs M2

  45. Some BACKUP slides by Daniela Borla's talk

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