Saggitarius dwarf - Max-Planck
Transcription
Saggitarius dwarf - Max-Planck
Dark Matter Search in TeV energy scale M.Teshima MPI für Physik, München (Werner-Heisenberg-Institut) On behalf of MAGIC collaboration MAGIC has started the operation!! (Major Atmospheric Gamma Imaging Cherenkov Telescope) Preliminary Observation Mrk421 in Feb (100mins) by MAGIC The MAGIC Collaboration (14 INSTITUTIONS, ~100 PHYSICISTS) Institut de Física d'Altes Energies, Barcelona: Oscar Blanch, Juan Cortina, Eva Domingo, Enrique Fernández, Josef Flix, Markus Gaug, Javi López, Manel Martínez Universitat Autònoma de Barcelona: Carmen Baixeras, Carles Domingo, Lluis Font, Raul Orduna, Alejandro Sánchez, Andreu Torres Crimean Astrophysical Observatory: Arnold Stepanian University of California, Davis: Daniel Ferenc, Alvin Laille Division of Experimental Physics, University of Lodz: Maria Giller, Piotr Jacon, Dorota Sobczynska, Tadeusz Wibig Universidad Complutense, Madrid: Luis José Contreras, Victoria Fonseca, Marcos López, Emma Oña, Raquel Reyes Max-Planck-Institut für Physik, München: Rudolf K. Bock, José Antonio Coarasa, Markus Garczarczyk, Jurgen Gebauer, Florian Goebel, Eckart Lorenz, Keiichi Mase, Razmick Mirzoyan, Satoko Mizobuchi, David Paneque, Kenji Shinozaki, Masahiro Teshima, Nadia Tonello, Vincenzo Vitale, Robert Wagner, Wolfgang Wittek Dipartimento di Fisica, Università di Padova: Laura Alciati, Denis Bastieri, Ciro Bigongiari, Nicola Galante, Mosè Mariotti, Abelardo Moralejo, Donatella Pascoli, Luigi Peruzzo, Antonio Saggion, Villi Scalzotto Space Research Unit, Potchefstroom University: Okkie C. de Jager Fachbereich Physik, Universität-GH Siegen: Thomas Hengstebeck, Nikolaj Pavel, Ralf Stiehler, Serguei Volkov Dipartimento di Fisica, Università di Siena: Mario Meucci, Riccardo Paoletti, R.Pegna, A.Piccioli, Antonio Stamerra, Nicola Turini Tuorla Observatory, Pikkiö: Aimo Sillanpää, Leo Takalo Universität Würzburg: Thomas Bretz, Eduardo Colombo, Tanja Kneiske, Karl Mannheim, Martin Merck Yerevan Physics Institute, Cosmic Ray Division, Yerevan: Ashot Chilingarian MAGIC Physics Objectives Pulsars Origin of Cosmic Rays SNRs AGNs Cosmological γ-Ray Horizon Quantum Gravity GRBs Cold Dark Matter By Kolb, 2003 Total Photon Spectrum from Neutralino annihilation (Bergstroem et al. 1998) Best Candidate; LSP Neutralino R-Parity conservation (100 GeV ≤ mχ ≤ 1TeV ) Neutralino Annihilations Æ gamma rays χχ → γγ χχ → γZ χχ → q q Φγ (Ω) = γ-line Eγ = mχ γ-line Eγ = mχ− mΖ2/4 mχ γ continuum Nγ vσ ⋅ ∫ ρDM (l )dl(Ω) 2 4π ⋅ M χ 2 Atmospheric Imaging Cherenkov Telescope Gamma ray Observe Cherenkov light from gamma ray showers Particle shower ~ 10 km ~ 1o C he re n k ov ligh t Effective area ~ 105m2 ~ 120 m Calorimetric !! ΔE/E~20% @ 100GeV Gamma/Hadron separation Gamma 300 GeV Height in km Height in km MC Simulation of Shower Angle in degrees Angle in degrees Gamma 20 km Radius in m Radius in m Angle in degrees Proton 1 TeV Hadron Rejection by Image ~99% Angle in degrees Hadron Alpha (Orientation angle) distribution Hadron rejection by orientation α~90% Gamma Rays C.R. Protons Before Image/Orientation cut After Image/Orientation cut NS/NB ~1/1000 NS/NB ~1/1 IACT vs. Satellite Complimentary Base Satellite Ground Gammaray detection Direct (pair creation) Indirect (atmospheric Cherenkov) Energy < 30 GeV (→ 100 GeV) >300 GeV (→ 30 GeV) Pros High S/N Large FOV Large area Good ⊿θ Cons Small area High cost Low S/N (CR bkgd.) (but imaging overcomes this!) Small FOV Signature of WIMP annihilation Preliminary Single telescope 50hrs Two telescopes 1000hrs Anatoly Klypin Dark Matter density profile SIS profile ∝r -2 Moore profile ∝r -1.5 NFW profile ∝r -1.0 Galactic Center distribution of DM Stoehr et al. 2003 Subhalo mass function ~10 degrees Annihilation rate S/N ratio Galactic Center is crowded - Galactic Center: all kinds of H.E. sources It´s just too crowded Most brilliant unid. EGRET source Central Black Hole X-ray flares! IACT Angular resolution Sgr A East non -thermal filaments (radio X-rayobjects sourcemay SNR Astronomical produce serious backgrounds!! Max-Planck Institute (Munich) – 11/9/2003 – Josep Flix (jflix@ifae.es) Today’s signal becomes B.G. in tomorrow!! Signals from G.C. perhaps these are B.G. for Dark matter search CANGAROO Whipple Energy Spectrum and time variation CANGAROO: Possible Time variation Whipple: No time variation CANGAROO observation suggests pion decay spectrum Nearby Dwarf Galaxies Sagittarius(South) Distance M/L Mass 24 kpc 100 M/L 5-20x108 M◎ Draco (North) Distance M/L Mass 79 kpc 440±240M/L 8x107 M◎ Clumping dark matter (A. Tasitsiomi and A. Olinto PRD2002) ~10% DM Æ clumps Clump M = 108M◎ Continuum Gamma Line Gamma Threshold Energy Dependence (A. Tasitsiomi and A. Olinto PRD2002) Extrapolation to 30GeV MAGIC Draco Dwarf Galaxy C.Tyler 2002 Summary Low threshold energy MAGIC is very effective to dark matter search. Dark Matter at the galactic center We are very close to the detection!! But not easy!! Normal astronomical sources DM density profile -- flatter than NFW? FOV of cherenkov telescope is too narrow? Æ Wide angle telescope is more effective!! Clumping Dark Matters Nearby dwarf galaxies, globular clusters are good candidates Compact and less background than G.C. High M/L Draco, Sagittarius dwarf galaxies are very interesting We have started the construction of second telescope (MAGIC II). Construction will be completed in 2006. It will improve the sensitivity and increase the flexibility of observation Dedicated program; search for Dark matter, AGNs patrol MAGIC and MAGIC II will observe G.C. and dwarf galaxies to search for dark matters