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Igor V. Moskalenko NASA Goddard Space Flight Center moskalenko@gsfc.nasa.gov with Andy W. StrongStepan G. Mashnik Andy W. Strong (MPE, Germany) & Stepan G. Mashnik (LANL) Propagation of Cosmic Rays and Diffuse Galactic Gamma Rays (nuclear physics in cosmic ray studies)
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Igor V. Moskalenko/NASA-GSFC 2 Nuclear Data-2004/09/26-10/1Santa Fe, NM All Particle CR Spectrum Energetically SNR – most probable sources of CR: ~5x10 49 erg per SN (1/30 yr -1 ) – 5% of the kinetic energy of the ejecta. CR propagate in the Galaxy for some 10 Myr before escape. Synchrotron radiation of ultra- relativistic electrons: evidence of particle acceleration, but not protons…
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Igor V. Moskalenko/NASA-GSFC 3 Nuclear Data-2004/09/26-10/1Santa Fe, NM EGRET Sky: “GeV Excess” The diffuse γ-ray emission is the dominant feature of the γ-ray sky – an evidence of CR interactions in the interstellar medium: bremsstrahlung, IC, π 0 Hunter et al. 1997 Excess
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Igor V. Moskalenko/NASA-GSFC 4 Nuclear Data-2004/09/26-10/1Santa Fe, NM Reacceleration Model: Secondary Pbars B/C ratioAntiproton flux E k, GeV/nucleon E k, GeV
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Igor V. Moskalenko/NASA-GSFC 5 Nuclear Data-2004/09/26-10/1Santa Fe, NM Positron Excess ? Are all the excesses connected somehow ? A signature of a new physics (DM) ? Caveats: Systematic errors ? A local source of primary positrons ? Large E-losses -> local spectrum… HEAT (Coutu et al. 1999) Leaky-Box GALPROP e + /e E, GeV 110100
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Igor V. Moskalenko/NASA-GSFC 6 Nuclear Data-2004/09/26-10/1Santa Fe, NM Propagation of Cosmic Rays: Why? Modeling of the CR propagation and diffuse gamma- ray emission requires to combine many different kinds of data obtained from astrophysical observations, and nuclear and particle physics experiments. Why Do We Need to Study CR Propagation ? In return, a correct model provides a basis for many studies in Astrophysics, Particle Physics, and Cosmology
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Igor V. Moskalenko/NASA-GSFC 7 Nuclear Data-2004/09/26-10/1Santa Fe, NM Dark Matter Signatures in CR Diffuse gammasAntiprotons E k, GeVE, GeV Well... But where is the nuclear physics?!
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Igor V. Moskalenko/NASA-GSFC 8 Nuclear Data-2004/09/26-10/1Santa Fe, NM CR Propagation: Milky Way Galaxy Halo Gas, sources 100 pc 40 kpc 4-12 kpc 0.1-0.01/ccm 1-100/ccm Intergalactic space 1 kpc~3x10 18 cm R Band image of NGC891 1.4 GHz continuum (NVSS), 1,2,…64 mJy/ beam Optical image: Cheng et al. 1992, Brinkman et al. 1993 Radio contours: Condon et al. 1998 AJ 115, 1693 NGC891 Sun
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Igor V. Moskalenko/NASA-GSFC 9 Nuclear Data-2004/09/26-10/1Santa Fe, NM CR Interactions in the Interstellar Medium e + - Sources: SNRs, Shocks, Superbubbles Particle acceleration Photon emission P He CNO X,γ gas BISRF π e + - + - P _ LiBeB ISM diffusion energy losses reacceleration convection etc. π 0 synchrotron IC bremss Chandra GLAST ACE BESS Halo disk escape He CNO solar modulation AMS p
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Igor V. Moskalenko/NASA-GSFC 10 Nuclear Data-2004/09/26-10/1Santa Fe, NM Heliosphere Flux 20 GeV/n
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Igor V. Moskalenko/NASA-GSFC 11 Nuclear Data-2004/09/26-10/1Santa Fe, NM Transport Equation ψ(r,p,t) – ψ(r,p,t) – density per total momentum sources (SNR, nuclear reactions…) convection diffusion diffusive reacceleration E-loss convection fragmentation radioactive decay
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Igor V. Moskalenko/NASA-GSFC 12 Nuclear Data-2004/09/26-10/1Santa Fe, NM Elemental Abundances: CR vs. Solar System CR abundances: ACE Solar system abundances LiBeB CNO F Fe ScTiV CrMn Si Cl Al O Volatility Na S
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Igor V. Moskalenko/NASA-GSFC 13 Nuclear Data-2004/09/26-10/1Santa Fe, NM Nuclear component in CR: What we can learn? Propagation parameters: Diffusion coeff., halo size, Alfvén speed, convection velosity… Energy markers: Reacceleration, solar modulation Local medium: Local Bubble Material & acceleration sites, nucleosynthesis (r- vs. s-processes) Stable secondaries: Li, Be, B, Sc, Ti, V Radio (t 1/2 ~1 Myr): 10 Be, 26 Al, 36 Cl, 54 Mn K-capture: 37 Ar, 49 V, 51 Cr, 55 Fe, 57 Co Short t 1/2 radio 14 C & heavy Z>30 Heavy Z>30: Cu, Zn, Ga, Ge, Rb Nucleo- synthesis: supernovae, early universe, Big Bang… Solar modulation Extragalactic diffuse γ- rays: blazars, relic neutralino Dark Matter (p,đ,e +,γ) -
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Igor V. Moskalenko/NASA-GSFC 14 Nuclear Data-2004/09/26-10/1Santa Fe, NM Fixing Propagation Parameters: Standard Way Using secondary/primary nuclei ratio: Diffusion coefficient and its index Propagation mode and its parameters (e.g., reacceleration V A, convection V z ) Radioactive isotopes: Galactic halo size Z h Z h increase B/C Be 10 /Be 9 Interstellar E k, MeV/nucleon
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Igor V. Moskalenko/NASA-GSFC 15 Nuclear Data-2004/09/26-10/1Santa Fe, NM stripping 51 Cr attachment Time scale (years) EC decay E k, MeV/nucleon K-capture isotopes Niebur et al. 2003 51 V/ 51 Cr E k, MeV/nucleon 51 V/ 51 Cr ≡ daughter/parent Electron attachment & stripping Solar modulation effect Jones et al. 2001 51 V/ 51 Cr E k, MeV/nucleon K-capture & reacceleration ISM
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Igor V. Moskalenko/NASA-GSFC 16 Nuclear Data-2004/09/26-10/1Santa Fe, NM First Ionization Potential (FIP) vs. Volatility Low-FIP ~ Refractories Rb, Cs – break the rule Other important elements: Na, Cu, Zn, Ga, Ge, Pb Rb Cs K Pb Ge Ga Na Zn Se Cu ~10 4 K
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Igor V. Moskalenko/NASA-GSFC 17 Nuclear Data-2004/09/26-10/1Santa Fe, NM Effect of Cross Sections: Radioactive Secondaries Different size from different ratios… Z halo,kp c ST W 27 Al+p 26 Al Errors in CR measurements (HE & LE)Errors in CR measurements (HE & LE) Errors in production cross sectionsErrors in production cross sections Errors in the lifetime estimatesErrors in the lifetime estimates Different origin of elements (Local Bubble ?)Different origin of elements (Local Bubble ?) nat Si+p 26 Al W ST T 1/2 = ? E k, MeV/nucleon
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Igor V. Moskalenko/NASA-GSFC 18 Nuclear Data-2004/09/26-10/1Santa Fe, NM Bigger picture…
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Igor V. Moskalenko/NASA-GSFC 19 Nuclear Data-2004/09/26-10/1Santa Fe, NM Matter, Dark Matter, Dark Energy… Ω ≡ ρ/ρ crit Ω tot =1.02 +/−0.02 Ω Matter =4.4%+/−0.4% Ω DM =23% +/−4% Ω Vacuum =73% +/−4% Supersymmetry is a mathematically beautiful theory, and would give rise to a very predictive scenario, if it is not broken in an unknown way which unfortunately introduces a large number of unknown parameters… Lars Bergström (2000) SUSY DM candidate has also other reasons to exist -particle physics…
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Igor V. Moskalenko/NASA-GSFC 20 Nuclear Data-2004/09/26-10/1Santa Fe, NM Example “Global Fit:” diffuse γ’s, pbars, positrons Look at the combined (pbar,e +,γ) data Possibility of a successful “global fit” can not be excluded -non-trivial ! If successful, it may provide a strong evidence for the SUSY DM pbars e+e+ γ GALPROP/W. de Boer et al. hep-ph/0309029 Supersymmetry: MSSM Lightest neutralino χ 0 m χ ≈ 100-500 GeV S=½ Majorana particles χ 0 χ 0 −> p, pbar, e +, e −, γ
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Igor V. Moskalenko/NASA-GSFC 21 Nuclear Data-2004/09/26-10/1Santa Fe, NM CR Fluctuations/SNR stochastic events GeV electrons 100 TeV electrons GALPROP/Credit S.Swordy Electron energy losses 10 7 yr 10 6 yr Bremsstrahlung 1 TeV Ionization Coulomb IC, synchrotron 1 GeV Ekin, GeV E(dE/dt) -1,yr Historical variations of CR intensity over 150 000 yr (Be 10 in South Polar ice) Konstantinov et al. 1990
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Igor V. Moskalenko/NASA-GSFC 22 Nuclear Data-2004/09/28, Santa Fe GeV excess: Optimized model Uses all sky and antiprotons & gammas to fix the nucleon and electron spectra Uses antiprotons to fix the intensity of CR nucleons @ HE Uses gammas to adjust the nucleon spectrum at LE the intensity of the CR electrons (uses also synchrotron index) Uses EGRET data up to 100 GeV protons electrons x4 x1.8 antiprotons E k, GeV
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Igor V. Moskalenko/NASA-GSFC 23 Nuclear Data-2004/09/26-10/1Santa Fe, NM Longitude Profiles |b|<5° 50-70 MeV 2-4 GeV 0.5-1 GeV 4-10 GeV
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Igor V. Moskalenko/NASA-GSFC 24 Nuclear Data-2004/09/26-10/1Santa Fe, NM Extragalactic Gamma-Ray Background Predicted vs. observed E, MeV E 2 xF Sreekumar et al. 1998 Strong et al. 2004 Elsaesser & Mannheim, astro-ph/0405235 Blazars Cosmological neutralinos E, GeV
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Igor V. Moskalenko/NASA-GSFC 25 Nuclear Data-2004/09/26-10/1Santa Fe, NM Conclusions I Accurate measurements of nuclear species in CR, secondary antiprotons, and diffuse γ-rays simultaneously may provide a new vital information for Astrophysics – in broad sense, Particle Physics, and Cosmology. Gamma rays: GLAST is scheduled to launch in 2007 – diffuse gamma rays is one of its priority goals CR species: New measurements at LE & HE simultaneously are highly desirable (Pamela, Super-TIGER, AMS…), also sec. positrons ! Hunter et al. region: l=300°-60°,|b|<10° Dark Matter Z h increase Be 10 /Be 9 E k, MeV/nucleon B/C E k, MeV/nucleon
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Igor V. Moskalenko/NASA-GSFC 26 Nuclear Data-2004/09/26-10/1Santa Fe, NM Conclusions II Antiprotons: Pamela (2005), AMS (2008) and a new BESS-polar instrument to fly a long- duration balloon mission (in 2004, 2006…), we thus will have more accurate and restrictive antiproton data HE electrons: Several missions are planned to target specifically HE electrons We must be ready…! GALPROP is a propagation model to play now; the accuracy depends very much on the accuracy of the nuclear production cross sections
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Igor V. Moskalenko/NASA-GSFC 27 Nuclear Data-2004/09/26-10/1Santa Fe, NM Thank you !
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