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Gamma-ray Large Area Space Telescope -France -Germany -Italy -Japan -Sweden -USA Energy Range 10 keV-300 GeV. GLAST : - An imaging gamma-ray telescope (LAT) -A second instrument for the study of Gamma Ray Bursts (GBM). Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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ACD contains 16 towers and each tower is divided in two parts: -the TRACKER (TKR): 18 layers in each tower -Tungsten converters (1.08 χ 0 : 78% prob) -2 orthogonal SSD planes of silicon microstrip sensors for detecting the electromagnetic shower -a CALORIMETER (CAL) of CsI crystals dopped by Tl; so the energy deposited by the EM shower is converted in light signal. CAL is characterized by fast decaying fluorescent light (~ns) and a long decaying afterglow (~ms). The main instrument of GLAST is the Large Area Telescope (LAT): a pair conversion telescope: Anticoincidence Shield (ACD) made of plastic scintillator(Bicron-408) sensitive to charged particles; ACD is segmented to avoid self veto from Calorimeter backsplash and also for micrometeorites. TRACKER CALORIMETER ANTICOINCIDENCE SHIELD Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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QuantityEGRETLAT (Minimim Spec.) Energy Range20 MeV - 30 GeV20 MeV - 300 GeV Peak Effective Area (after background rejection) 1500 cm²> 8000 cm² Field of View0.5 sr> 2 sr Angular Resolution5.8° (100 MeV) 10 GeV) Energy Resolution10%< 10% Deadtime per Event100 ms< 100 μs Source Location Determination15'< 0.5' Point Source Sensitivity~ 10 -7 cm -2 s -1 < 6 x 10 -9 cm -2 s -1 LAT Specifications and Performance Compared with EGRET Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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QuantityEGRETLAT (Minimim Spec.) Energy Range20 MeV - 30 GeV20 MeV - 300 GeV Peak Effective Area (after background rejection) 1500 cm²> 8000 cm² Field of View0.5 sr> 2 sr Angular Resolution5.8° (100 MeV) 10 GeV) Energy Resolution10%< 10% Deadtime per Event100 ms< 100 μs Source Location Determination15'< 0.5' Point Source Sensitivity~ 10 -7 cm -2 s -1 < 6 x 10 -9 cm -2 s -1 LAT Specifications and Performance Compared with EGRET Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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The Glast Burst Monitor (GBM) will include two sets of detectors: -12 sodium iodide (NaI) scintillators -2 cylindrical bismuth germanate (BGO) scintillators The NaI detectors are sensitive in the lower end of the energy range, from a few keV to about 1 MeV and provide burst triggers and locations. The BGO detectors cover the energy range ~150 keV to ~ 30 MeV, providing a good overlap with the NaI at the lower end and with the LAT at the higher end. Schematic layout of the 12 NaI and two BGO detectors on the GLAST spacecraft Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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QuantityBATSEGBM (Minimum Spec.) Energy Range25 keV - 10 MeV 25 MeV Field of View4π srall sky not occulted by the Earth Energy Resolution< 10% Deadtime per Event< 15 μs Burst Sensitivity0.2 cm -2 s -1 < 0.5 cm -2 s -1 GRB Alert Location~ 25°< 15° GRB Final Location1.7°< 1.5° GBM Specifications and Performance Compared with BATSE Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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AGN/BLAZARS UNIDENTIFIED EGRET SOURCES NEW PARTICLE PHYSICS EXTRAGALACTIC BACKGROUND LIGHT GAMMA-RAY BURSTS PULSARS COSMIC RAYS AND INTERSTELLAR EMISSION SOLAR FLARES Scientific purposes Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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AGN/BLAZARS UNIDENTIFIED EGRET SOURCES NEW PARTICLE PHYSICS EXTRAGALACTIC BACKGROUND LIGHT GAMMA-RAY BURSTS PULSARS COSMIC RAYS AND INTERSTELLAR EMISSION SOLAR FLARES Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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AGN/BLAZARS UNIDENTIFIED EGRET SOURCES NEW PARTICLE PHYSICS EXTRAGALACTIC BACKGROUND LIGHT GAMMA-RAY BURSTS PULSARS COSMIC RAYS AND INTERSTELLAR EMISSION SOLAR FLARES And other extremely important features are the COMPLEMENTARITY WITH GROUND-BASED GAMMA- RAY TELESCOPES and that GLAST will study the Universe in UNEXPLORED REGIONS OF EM SPECTRUM. Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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AGN/BLAZARS UNIDENTIFIED EGRET SOURCES NEW PARTICLE PHYSICS EXTRAGALACTIC BACKGROUND LIGHT GAMMA-RAY BURSTS PULSARS COSMIC RAYS AND INTERSTELLAR EMISSION SOLAR FLARES And other extremely important features are the COMPLEMENTARITY WITH GROUND-BASED GAMMA- RAY TELESCOPES and that GLAST will study the Universe in UNEXPLORED REGIONS OF EM SPECTRUM. Scientific purposes Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005
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Background rejection with Classification Trees using R. -Signal file ( ag-v3r3p7-merituple-prune20031218-fulltup.root) 722594 γ (power law, isotropic 4 ) -27 BKG files ( ntuple_prune*.root) 5551326 eventi : p, e -, e +, albedo γ Before bkg rejection with R CT was made in a single step: 0 signal 1 bkg A day of “real” data (part of Data Challenge 1). Omar Tibolla. ISAPP. Belgirate (Italy) 30 June- 9 July 2005 I tried to do it in 2 steps: 1º: separate from charged particles. 2º: separate with the same method signal and albedo 0 charged particle 1 γ 2 γ sign 3 γ albedo
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Conclusions -Big improvements using matrix of costs, expecially in high energy bins. -Problems with second steps.
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Conclusions (2)
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