Igor V. Moskalenko (Stanford) Challenges in Astrophysics of CR (knee--) & γ-rays  Intro to the relevant physics  Some of the challenges…  Modeling of the CR propagation and diffuse emission  Perspectives: Pamela, GLAST and other near future missions

Igor V. Moskalenko 2 December 12, 2005TA-seminar/Fermilab 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 December 12, 2005TA-seminar/Fermilab 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 December 12, 2005TA-seminar/Fermilab 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 December 12, 2005TA-seminar/Fermilab 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 December 12, 2005TA-seminar/Fermilab Transport Equations ~90 (no. of CR species) ψ(r,p,t) – ψ(r,p,t) – density per total momentum sources (SNR, nuclear reactions…) convection convection (Galactic wind) diffusion diffusive reacceleration diffusive reacceleration (diffusion in the momentum space) E-loss fragmentation radioactive decay + boundary conditions

Igor V. Moskalenko 7 December 12, 2005TA-seminar/Fermilab CR Propagation: Milky Way Galaxy Halo Gas, sources 100 pc 40 kpc 4-12 kpc /ccm 1-100/ccm Intergalactic space 1 kpc ~ 3x10 18 cm R Band image of NGC GHz continuum (NVSS), 1,2,…64 mJy/ beam Optical image: Cheng et al. 1992, Brinkman et al Radio contours: Condon et al AJ 115, 1693 NGC891 Sun “Flat halo” model (Ginzburg & Ptuskin 1976) Halo

Igor V. Moskalenko 8 December 12, 2005TA-seminar/Fermilab 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 9 December 12, 2005TA-seminar/Fermilab 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 10 December 12, 2005TA-seminar/Fermilab Peak in the Secondary/Primary Ratio Leaky-box model: fitting path-length distribution -> free function B/C Diffusion models:  Diffusive reacceleration  Convection  Damping of interstellar turbulence  Etc. Accurate measurements in a wide energy range may help to distinguish between the models E k, MeV/nucleon too sharp max?

Igor V. Moskalenko 11 December 12, 2005TA-seminar/Fermilab Distributed Stochastic Reacceleration Fermi 2-nd order mechanism B Scattering on magnetic turbulences D pp ~ p 2 V a 2 /D D ~ vR 1/3 - Kolmogorov spectrum I cr E strong reacceleration weak reacceleration ΔEΔE Simon et al Seo & Ptuskin /3 D xx = 5.2x10 28 (R/3 GV) 1/3 cm -2 s -1 V a = 36 km s -1 γ ~ R -δ, δ=1.8/2.4 below/above 4 GV

Igor V. Moskalenko 12 December 12, 2005TA-seminar/Fermilab Convection Galactic wind Escape length Xe E v R -0.6 wind or turbulent diffusion resonant diffusion Jones 1979 problem: too broad sec/prim peak D~R 0.6 D xx = 2.5x10 28 (R/4 GV) 0.6 cm -2 s -1 dV/dz = 10 km s -1 kpc -1 γ ~ R -δ, δ=2.46/2.16 below/above 20 GV

Igor V. Moskalenko 13 December 12, 2005TA-seminar/Fermilab Damping of Interstellar Turbulence Iroshnikov-Kraichnan cascade: Kolmogorov cascade: W(k) k dissipation 1/10 12 cm 1/10 20 cm Simplified case: 1-D diffusion No energy losses Mean free path nonlinear cascade Ptuskin et al. 2003, 2005

Igor V. Moskalenko 14 December 12, 2005TA-seminar/Fermilab LiBeB: Major Production Channels Propagated Abundance * Cross-section Be B C Li N O Li Well defined (65%): C 12, O 16 ->LiBeB N 14 -> Be 7 (see Moskalenko & Mashnik 28 ICRC, 2003) Few measurements: C 13,N -> LiBeB B -> BeB Unknown: LiBeB,C 13,N -> LiBeB  “Tertiary” reactions also important! -35% A=

Igor V. Moskalenko 15 December 12, 2005TA-seminar/Fermilab 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

Igor V. Moskalenko 16 December 12, 2005TA-seminar/Fermilab Wherever you look, the GeV  -ray excess is there ! 4a-f EGRET data Excess: x2

Igor V. Moskalenko 17 December 12, 2005TA-seminar/Fermilab 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 18 December 12, 2005TA-seminar/Fermilab 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 19 December 12, 2005TA-seminar/Fermilab CR Source Distribution SNR source The CR source (SNRs, pulsars) distribution is too narrow to match the CR distribution in the Galaxy assuming X CO =N(H 2 )/W CO =const (CO is a tracer of H 2 ) Lorimer 2004 Pulsars CR after propagation diffuse γ-ray distribution

Igor V. Moskalenko 20 December 12, 2005TA-seminar/Fermilab CR Abundances at LE & HE (ACE vs HEAO-3) Fitting to measured CR abundances in the wide energy range (~0.1 – 30 GeV) is problematic. May indicate: systematic or cross- calibration errors different origin of LE and HE CR =(Calcs-Exp)/Exp Fit quality Relat. deviation

Igor V. Moskalenko 21 December 12, 2005TA-seminar/Fermilab Hypotheses… Provide good agreement with all data (diffuse gammas, pbars, e+)  CR intensity variations  Dark Matter signals Other possibilities: Harder CR spectrum (protons, electrons) – deviates limits from pbars, gamma-ray profiles Influence of the Local Bubble (local component) – helps with pbars, but doesn’t help with diffuse gammas

Igor V. Moskalenko 22 December 12, 2005TA-seminar/Fermilab 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 23 December 12, 2005TA-seminar/Fermilab CR Variations in Space & Time Historical variations of CR intensity: ~40kyr ( 10 Be in South Polar ice), ~2.8Myr ( 60 Fe in deep sea FeMn crust) Konstantinov et al Electron/positron energy losses Different “collecting” areas A vs. p (σ~30 mb) (different sources ?) SNR number density R, kpc sun More frequent SN in the spiral arms

Igor V. Moskalenko 24 December 12, 2005TA-seminar/Fermilab 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 25 December 12, 2005TA-seminar/Fermilab 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 26 December 12, 2005TA-seminar/Fermilab 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 27 December 12, 2005TA-seminar/Fermilab 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 28 December 12, 2005TA-seminar/Fermilab Longitude Profiles |b|<5° MeV 2-4 GeV GeV 4-10 GeV

Igor V. Moskalenko 29 December 12, 2005TA-seminar/Fermilab Latitude Profiles: Inner Galaxy MeV 2-4 GeV0.5-1 GeV 4-10 GeV20-50 GeV

Igor V. Moskalenko 30 December 12, 2005TA-seminar/Fermilab Latitude Profiles: Outer Galaxy MeV 2-4 GeV GeV 4-10 GeV

Igor V. Moskalenko 31 December 12, 2005TA-seminar/Fermilab 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 32 December 12, 2005TA-seminar/Fermilab 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 33 December 12, 2005TA-seminar/Fermilab Distribution of CR Sources & Gradient in the CO/H 2 CR distribution from diffuse gammas (Strong & Mattox 1996) SNR distribution (Case & Bhattacharya 1998) sun X CO =N(H 2 )/W CO : Histo –This work, Strong et al.’ Sodroski et al.’95,’97 1.9x Strong & Mattox’96 ~Z -1 – Boselli et al.’02 ~Z Israel’97,’00, [O/H]=0.04,0.07 dex/kpc Pulsar distribution Lorimer 2004

Igor V. Moskalenko 34 December 12, 2005TA-seminar/Fermilab Again Diffuse Galactic Gamma Rays More IC in the GC – better agreement ! The pulsar distribution vs. R falls too fast OR larger H 2 /CO gradient Very good agreement ! 2-4 GeV

Igor V. Moskalenko 35 December 12, 2005TA-seminar/Fermilab E.Bloom’05

Igor V. Moskalenko 36 December 12, 2005TA-seminar/Fermilab 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 37 December 12, 2005TA-seminar/Fermilab Where is the DM ?! What (flavors):  Neutrinos ~ visible matter  Super-heavy relics: “wimpzillas”  Axions  Topological objects “Q-balls” Neutralino-like, KK-like Where (places): 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 –CR, γ’s (PAMELA,GLAST,BESS) from E.Bloom presentation

Igor V. Moskalenko 38 December 12, 2005TA-seminar/Fermilab 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 ! pbars e+e+ γ GALPROP/W. de Boer et al. hep-ph/ Supersymmetry:  MSSM (DarkSUSY)  Lightest neutralino χ 0  m χ ≈ GeV  S=½ Majorana particles  χ 0 χ 0 −> p, pbar, e +, e −, γ

Igor V. Moskalenko 39 December 12, 2005TA-seminar/Fermilab Longitude and Latitude Distr. E >0.5 GeV In the plane (± 5 0 in lat.) Out of the plane (± 30 0 in long.. )

Igor V. Moskalenko 40 December 12, 2005TA-seminar/Fermilab x y z 2003, Ibata et al, Yanny et al. Outer Ring Inner Ring DM halo disk bulge Rotation Curve xy xz xy xz Expected Profile (NFW) Halo profile Isothermal Profile v 2  M/r=cons. and  M/r 3  1/r 2 for const. rotation curve Observed Profile: EGRET data + GALPROP Executive Summary –de Boer et al. astro-ph/

Page Number PAMELA: Secondary to Primary ratios plots: M.Simon  LE: sec/prim peak: one instrument -no cross calibration errors  HE: D xx (R)

Igor V. Moskalenko 42 December 12, 2005TA-seminar/Fermilab PAMELA positrons  A factor of 2 will become statistically significant  Measuring absolute flux not ratio  Solar minimum conditions After 3 years

Igor V. Moskalenko 43 December 12, 2005TA-seminar/Fermilab PAMELA antiprotons After 3 years

Igor V. Moskalenko 44 December 12, 2005TA-seminar/Fermilab

Igor V. Moskalenko 45 December 12, 2005TA-seminar/Fermilab A.Morselli

Igor V. Moskalenko 46 December 12, 2005TA-seminar/Fermilab GLAST LAT simulations EGRET intensity (>100 MeV) LAT simulation (>100 MeV) |b| < 20° Seth Digel

Igor V. Moskalenko 47 December 12, 2005TA-seminar/Fermilab GLAST LAT: The Gamma-Ray Sky EGRET (>100 MeV) Simulated LAT (>100 MeV, 1 yr) Simulated LAT (>1 GeV, 1 yr) This is an animation that steps from 1. EGRET (>100 MeV), to 2. LAT (>100 MeV), to 3. LAT (>1 GeV) Seth Digel

Igor V. Moskalenko 48 December 12, 2005TA-seminar/Fermilab Conclusions I Accurate measurements of nuclear species in CR, secondary positrons, 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 (PAMELA, Super-TIGER, AMS…) 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

Igor V. Moskalenko 49 December 12, 2005TA-seminar/Fermilab Conclusions II Antiprotons: PAMELA (2006), 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 In few years we may expect major breakthroughs in Astrophysics and Particle Physics ! CERN Large Hadronic Collider – will address SUSY Positrons: PAMELA (2006), AMS (2008): accurate and restrictive positron data

Igor V. Moskalenko 50 December 12, 2005TA-seminar/Fermilab Thank you !

Igor V. Moskalenko 51 December 12, 2005TA-seminar/Fermilab Backup slides

Igor V. Moskalenko 52 December 12, 2005TA-seminar/Fermilab Isotopic Production Cross Sections of LiBeB Semi-empirical systematics (Webber, ST) are not always correct. Results obtained by different groups are often inconsistent and hard to test. Very limited number of nuclear measurements: Evaluating the cross section is very laborious and can’t be done without modern nuclear codes. Use LANL nuclear database and modern computer codes. W ST