Igor V. Moskalenko (Stanford) GALPROP Model for Galactic CR propagation and diffuse γ -ray emission

Igor V. Moskalenko 2 October 24, 2006SCIPP/UCSC CR Interactions in the Interstellar Mediume+- PHeCNO X,γ gas ISRF e+- π+- P_LiBeB ISM diffusion energy losses energy losses reacceleration reacceleration convection convection etc. etc. π 0 synchrotron IC bremss Chandra GLAST ACE helio-modulation p 42 sigma ( data) HESS Preliminary SNR RX J PSF BHeCNO Flux 20 GeV/n CR species:  Only 1 location  modulation e+- π+- PAMELA BESS AMS

Igor V. Moskalenko 3 October 24, 2006SCIPP/UCSC 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 Long propagation history…

Igor V. Moskalenko 4 October 24, 2006SCIPP/UCSC 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 Diffuse γ-rays Galactic, extragalactic: blazars, relic neutralino Dark Matter (p,đ,e +,γ) -

Igor V. Moskalenko 5 October 24, 2006SCIPP/UCSC Diffuse Galactic Gamma-ray Emission ~80% of total Milky Way luminosity at HE !!! Tracer of CR (p, e − ) interactions in the ISM (π 0,IC,bremss): oStudy of CR species in distant locations (spectra & intensities)  CR acceleration (SNRs, pulsars etc.) and propagation oEmission from local clouds → local CR spectra  CR variations, Solar modulation oMay contain signatures of exotic physics (dark matter etc.)  Cosmology, SUSY, hints for accelerator experiments oBackground for point sources (positions, low latitude sources…) Besides: o“Diffuse” emission from other normal galaxies (M31, LMC, SMC)  Cosmic rays in other galaxies ! oForeground in studies of the extragalactic diffuse emission oExtragalactic diffuse emission (blazars ?) may contain signatures of exotic physics (dark matter, BH evaporation etc.) Calculation requires knowledge of CR (p,e) spectra in the entire Galaxy

Igor V. Moskalenko 6 October 24, 2006SCIPP/UCSC A Model of CR Propagation in the Galaxy  Gas distribution (energy losses, π 0, brems)  Interstellar radiation field (IC, e ± energy losses)  Nuclear & particle production cross sections  Gamma-ray production: brems, IC, π 0  Energy losses: ionization, Coulomb, brems, IC, synch  Solve transport equations for all CR species  Fix propagation parameters  “Precise” Astrophysics

Igor V. Moskalenko 7 October 24, 2006SCIPP/UCSC How It Works: Fixing Propagation Parameters Using secondary/primary nuclei ratio & flux: 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 E 2 Flux Carbon E k, GeV/nucleon

Igor V. Moskalenko 8 October 24, 2006SCIPP/UCSC Wherever you look, the GeV  -ray excess is there ! 4a-f EGRET data Excess: x2

Igor V. Moskalenko 9 October 24, 2006SCIPP/UCSC Reacceleration Model vs. Plain Diffusion Plain Diffusion (D xx ~β -3 R 0.6 ) Diffusive Reacceleration B/C ratio Antiproton flux B/C ratio Excess: x2

Igor V. Moskalenko 10 October 24, 2006SCIPP/UCSC 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 (Beatty et al. 2004) GALPROP 1 E, GeV 10 e + /e HEAT 2000 HEAT HEAT combined 1 E, GeV 10 Q: Are all the excesses connected? A: “Yes” and “No” Same progenitor (CR p or DM) for pbars, e + ’s, γ’s Systematic errors of different detectors E > 6 GeV Excess: 20%

Igor V. Moskalenko 11 October 24, 2006SCIPP/UCSC Diffuse emission models GeV >0.5 GeV Dark Matter Cosmic Ray Spectral Variations EGRET “GeV Excess” There are two possible BUT fundamentally different explanations of the excess, in terms of exotic and traditional physics:  Dark Matter  CR spectral variations Both have their pros & cons. from Strong et al. ApJ (2004) from de Boer et al. A&A (2005) from Hunter et al. ApJ (1997)

Igor V. Moskalenko 12 October 24, 2006SCIPP/UCSC Electron Fluctuations/SNR stochastic events GeV electrons 100 TeV electrons GALPROP/Credit S.Swordy Energy losses 10 7 yr 10 6 yr Bremsstrahlung 1 TeV Ionization Coulomb IC, synchrotron 1 GeV Ekin, GeV E(dE/dt) -1,yr Electron energy loss timescale: 1 TeV: ~300 kyr 100 TeV: ~3 kyr

Igor V. Moskalenko 13 October 24, 2006SCIPP/UCSC GeV excess: Optimized/Reaccleration model Uses all sky and antiprotons & gammas to fix the nucleon and electron spectra  Uses antiprotons to fix the intensity of CR 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 pbars e + -flux γ-rays

Igor V. Moskalenko 14 October 24, 2006SCIPP/UCSC Secondary e ± are seen in γ-rays ! Lots of new effects ! Improves an agreement at LE brems IC Heliosphere: e + /e~0.2 electrons positrons sec.

Igor V. Moskalenko 15 October 24, 2006SCIPP/UCSC Diffuse Gammas at Different Sky Regions Intermediate latitudes: l=0°-360°,10°<|b|<20° Outer Galaxy: l=90°-270°,|b|<10° Intermediate latitudes: l=0°-360°,20°<|b|<60° Inner Galaxy: l=330°-30°,|b|<5° Hunter et al. region: l=300°-60°,|b|<10° l=40°-100°,|b|<5° corrected Milagro

Igor V. Moskalenko 16 October 24, 2006SCIPP/UCSC Longitude Profiles |b|<5° MeV 2-4 GeV GeV 4-10 GeV

Igor V. Moskalenko 17 October 24, 2006SCIPP/UCSC Latitude Profiles: Inner Galaxy MeV 2-4 GeV0.5-1 GeV 4-10 GeV20-50 GeV

Igor V. Moskalenko 18 October 24, 2006SCIPP/UCSC Latitude Profiles: Outer Galaxy MeV 2-4 GeV GeV 4-10 GeV

Igor V. Moskalenko 19 October 24, 2006SCIPP/UCSC Anisotropic Inverse Compton Scattering  Electrons in the halo see anisotropic radiation  Observer sees mostly head-on collisions e-e- e-e- head-on: large boost & more collisions γ γ small boost & less collisions γ sun Energy density Z, kpc R=4 kpc high latitudes !

Igor V. Moskalenko 20 October 24, 2006SCIPP/UCSC Effect of anisotropic ICS Galactic latitude, degrees Ratio anisoIC/isoIC Intermediate latitudes GC anti-GC pole The anisotropic IC scattering plays important role in modeling the Galactic diffuse emission Affects estimates of isotropic extragalactic background

Igor V. Moskalenko 21 October 24, 2006SCIPP/UCSC Latitude profile of the outer Galaxy anisotropic IC The aniso IC is maximal (x2) in the outer Galaxy around b=20  -30  Agreement with data impossible without aniso IC Latitude isoIC bremsstrahlung 00 Total EG PRELIMINARY

Igor V. Moskalenko 22 October 24, 2006SCIPP/UCSC Extragalactic Gamma-Ray Background Predicted vs. observed E, MeV E 2 xF Sreekumar et al Strong et al Elsaesser & Mannheim, astro-ph/ Blazars Cosmological neutralinos EGRB in different directions

Igor V. Moskalenko 23 October 24, 2006SCIPP/UCSC Inverse Compton scattering ©UCAR The heliosphere is filled with Galactic CR electrons and solar photons electrons are isotropic photons have a radial angular distribution QED e IM, T.Porter, S.Digel: astro-ph/

Igor V. Moskalenko 24 October 24, 2006SCIPP/UCSC The ecliptic Averaged over one year, the ecliptic will be seen as a bright stripe on the sky, but the emission comes from all directions Galactic plane GC ecliptic >100 MeV IS spectrum Modulated 500 MV Modulated 1000 MV >1 GeV Current EGRB AC 70°

Igor V. Moskalenko 25 October 24, 2006SCIPP/UCSC 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…

Igor V. Moskalenko 26 October 24, 2006SCIPP/UCSC Where is the DM ?! What (flavors):  Neutrinos ~ visible matter  Super-heavy relics: “wimpzillas”  Axions  Topological objects “Q-balls” Neutralino-like, KK-like Neutralino-like, KK-like Where (places): Galactic halo, Galactic center Galactic halo, Galactic center  The sun and the Earth How (tools):  Direct searches –low-background experiments (DAMA, EDELWEISS) –neutrino detectors (AMANDA/IceCUBE) –Accelerators (LHC) Indirect searches Indirect searches –CR, γ’s (PAMELA,GLAST,BESS) from E.Bloom presentation

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