GALPROP: principles, internal structure, recent results, and perspective

Transcription

1 GALPROP: principles, internal structure, recent results, and perspective Igor V. Moskalenko & Andy W. Strong NASA/GSFC MPE, Germany with Olaf Reimer Bochum,, Germany Topics to cover: GALPROP: principles, inputs/outputs, calculations Recent results (GeV( excess & pbars,, extragalactic background) Dark Matter Near future developments

2 Transport Equation r ψ (, t p, t ) = r q (, p ) sources (SNR, nuclear reactions ) diffusion + r [ D r r ψ V ψ ] xx convection diffusive reacceleration + p p 2 D pp p ψ p 2 E-loss p dp dt ψ 1 3 r p r V ψ convection fragmentation ψ τ f ψ τ d radioactive decay ψ(r,p,t) density per total momentum Igor V. Moskalenko/NASA-GSFC 2 GLAST meeting/slac 2004/09/27-30

3 CR Propagation: Milky Way Galaxy Optical image: Cheng et al. 1992, Brinkman et al Radio contours: Condon et al AJ 115, kpc~3x10 18 cm NGC pc Halo /ccm 40 kpc Gas, sources 1-100/ccm Sun 4-12 kpc R Band image of NGC GHz continuum (NVSS), 1,2, 64 mjy/ beam Intergalactic space Igor V. Moskalenko/NASA-GSFC 3 GLAST meeting/slac 2004/09/27-30

4 CR Interactions in the Interstellar Medium Halo disk Sources: SNRs, Shocks, Superbubbles Particle acceleration Photon emission P He CNO escape X,γ e + - diffusion energy losses reacceleration convection etc. π + - _ P p ISM gas e + - B solar modulation synchrotron ISRF gas π 0 LiBeB He CNO IC bremss ACE Chandra GLAST BESS AMS Igor V. Moskalenko/NASA-GSFC 4 GLAST meeting/slac 2004/09/27-30

5 Grids GALPROP Input: galdef-files GALPROP is parameter-driven (user can specify everything!) 2D/3D options; symmetry options (full 3D, 1/8 -quadrants) Spatial, energy/momentum, latitude & longitude grids Ranges: energy, R, x, y, z, latitude & longitude Time steps Propagation parameters D xx, V A, V C & injection spectra (p,e) X-factors (including R-dependence) Sources Parameterized distributions Known SNRs Random SNRs (with given/random spectra), time dependent eq. Other Source isotopic abundances, secondary particles (pbar, e ±, γ, synchro), anisotropic IC, energy losses, nuclear production cross sections Igor V. Moskalenko/NASA-GSFC 5 GLAST meeting/slac 2004/09/27-30

6 Grids Z R,x,y -1 Typical grid steps (can be arbitrary!) z = 0.1 kpc, z = 0.01 kpc (gas averaging) R = 1 kpc E = x1.2 (log-grid) Igor V. Moskalenko/NASA-GSFC 6 GLAST meeting/slac 2004/09/27-30

7 Gas Distribution Molecular hydrogen H 2 is traced using J=1-0 transition of 12 CO, concentrated mostly in the plane (z~70 pc, R<10 kpc) Atomic hydrogen H I has a wider distribution (z~1 kpc, R~30 kpc) Sun Ionized hydrogen H II small proportion, but exists even in halo (z~1 kpc) Igor V. Moskalenko/NASA-GSFC 7 GLAST meeting/slac 2004/09/27-30

8 Energy density Interstellar Radiation Field Stellar Dust CMB Energy density Sun Igor V. Moskalenko/NASA-GSFC 8 GLAST meeting/slac 2004/09/27-30

9 Nuclear Reaction Network+Cross Sections Secondary, radioactive ~1 Myr & K-capture isotopes Co57 55 Fe Mn 54 Cr 51 V 49 p,ec,β + Al 26 Ar 37 Cl 36 Ca 41 β -, n Be 7 Be 10 Plus some dozens of more complicated reactions. But many cross sections are not well known Igor V. Moskalenko/NASA-GSFC 9 GLAST meeting/slac 2004/09/27-30

10 Nuclear component in CR: What we can learn? 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 Propagation parameters: Diffusion coeff., halo size, Alfvén speed, convection velosity Energy markers: Reacceleration, solar modulation Local medium: Local Bubble Material & acceleration sites, nucleosynthesis (rvs. s-processes) Nucleosynthesis: supernovae, early universe, Big Bang Diffuse γ-rays Galactic, extragalactic: blazars, relic neutralino Dark Matter (p,đ,e +,γ) - Solar modulation Igor V. Moskalenko/NASA-GSFC 10 GLAST meeting/slac 2004/09/27-30

11 Fixing Propagation Parameters: Standard Way B/C Interstellar Using secondary/primary nuclei ratio: Diffusion coefficient and its index Propagation mode and its parameters (e.g., reacceleration V A, convection V z ) Be 10 /Be 9 E k, MeV/nucleon Radioactive isotopes: Galactic halo size Z h Z h increase E k, MeV/nucleon Igor V. Moskalenko/NASA-GSFC 11 GLAST meeting/slac 2004/09/27-30

12 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. Measuring many isotopes in CR simultaneously may help to distinguish Igor V. Moskalenko/NASA-GSFC 12 GLAST meeting/slac 2004/09/27-30

13 Heliosphere Flux 20 GeV/n Igor V. Moskalenko/NASA-GSFC 13 GLAST meeting/slac 2004/09/27-30

14 Electron Fluctuations/SNR stochastic events GeV electrons 100 TeV electrons GALPROP/Credit S.Swordy E(dE/dt) -1,yr 10 7 yr 10 6 yr Energy losses Bremsstrahlung Ionization IC, synchrotron Coulomb 1 GeV 1 TeV Ekin, GeV Electron energy loss timescale: 1 TeV: ~ yr 100 TeV: ~3 000 yr Igor V. Moskalenko/NASA-GSFC 14 GLAST meeting/slac 2004/09/27-30

15 CR Variations in Space & Time More frequent SN in the spiral arms Historical variations of CR intensity over yr (Be 10 in South Polar ice) Electron/positron energy losses Konstantinov et al Different collecting areas A vs. p Igor V. Moskalenko/NASA-GSFC 15 GLAST meeting/slac 2004/09/27-30

16 GALPROP Output/FITS files Provides literally everything: All nuclei and particle spectra in every grid point (x,y,r,z,e) -FITS files Separately for π 0 -decay, IC, bremsstrahlung: Emissivities in every grid point (x,y,r,z,e,process) Skymaps with a given resolution (l,b,e,process) CONSUMERS: AMS, Pamela dark matter searches ACE, TIGER interpretation of isotopic abundances HEAT electrons, positrons GLAST(?) spectrum of the diffuse emission & background model Igor V. Moskalenko/NASA-GSFC 16 GLAST meeting/slac 2004/09/27-30

17 algorithm numerical solution of cosmic-ray transport primary 2D or 3D source grid functions (p, He, C... Ni) source time-independent abundances, or spectra time-dependent primary propagation -starting from maxa=64 source functions (Be, B..., e +,e -, pbars) using primaries and gas distributions secondary propagation tertiary source functions tertiary propagation γ-rays (IC, bremsstrahlung, π o -decay) radio: synchrotron Igor V. Moskalenko/NASA-GSFC 17 GLAST meeting/slac 2004/09/27-30

18 GALPROP Calculations Constraints Bin size (x,y,z) depends on the computer speed, RAM; final run can be done on a very fine grid! No other constraints! any required process/formalism can be implemented; vectorization!! Calculations (γ -ray related) Vectorization options Heliospheric modulation: routinely force-field, can use Potgieter model 1. For a given propagation parameters: propagate p, e, nuclei, secondaries (currently in 2D) 2. The propagated distributions are stored 3. With propagated spectra: calculate the emissivities (π 0 -decay, IC, bremss) in every grid point 4. Integrate the emissivities over the line of sight: GALPROP has a full 3D grid, but currently only 2D gas maps (H2, H I, H II) Using actual annular maps (column density) at the final step High latitudes above b=40 -using integrated H I distribution Igor V. Moskalenko/NASA-GSFC 18 GLAST meeting/slac 2004/09/27-30

19 Near Future Developments Full 3D Galactic structure: 3D gas maps (from S.Digel, S.Hunter and/or smbd else) 3D interstellar radiation & magnetic fields (A.Strong & T.Porter) Cross sections: Blattnig et al. formalism for π 0 -production Diffractive dissociation with scaling violation (T.Kamae) Isotopic cross sections (with S.Mashnik, LANL; try to motivate BNL, JENDL-Japan, other Nuc. Data Centers) Energy range: Extend toward sub-mev range to compare with INTEGRAL diffuse emission (continuum; 511 kev line) Modeling the local structure: Local SNRs with known positions and ages Local Bubble may be done at the final calculation step Heliospheric modulation: Implementing a complimentary drift model by M.Potgieter Visualization tool (started) using the classes of CERN ROOT package: images, profiles, and spectra from GALPROP to be directly compared with data Improving the GALPROP module structure (for DM studies) & developing a dedicated Web-site to allow for a communication with users Igor V. Moskalenko/NASA-GSFC 19 GLAST meeting/slac 2004/09/27-30

20 Recent results Igor V. Moskalenko/NASA-GSFC 20 GLAST meeting/slac 2004/09/27-30

21 Wherever you look, the GeV γ - ray excess is there! Igor V. Moskalenko/NASA-GSFC 21 GLAST meeting/slac 2004/09/ a-f

22 Reacceleration Model: Secondary Pbars B/C ratio Antiproton flux E k, GeV/nucleon E k, GeV Igor V. Moskalenko/NASA-GSFC 22 GLAST meeting/slac 2004/09/27-30

23 Positron Excess? HEAT (Coutu et al. 1999) e + /e GALPROP Leaky-Box E, GeV 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 E -> > local spectrum Igor V. Moskalenko/NASA-GSFC 23 GLAST meeting/slac 2004/09/27-30

24 Matter, Dark Matter, Dark Energy Visible atoms Dark Energy Dark Matter Ω ρ/ρ crit =1.02 +/ 0.02 Ω tot Ω Matter =4.4% +/ 0.4% Ω DM =23% +/ 4% Ω Vacuum =73% +/ 4% SUSY DM candidate has also other reasons to exist -particle physics 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) Igor V. Moskalenko/NASA-GSFC 24 GLAST meeting/slac 2004/09/27-30

25 Example Global Fit: diffuse γ s, pbars, positrons GALPROP/W. de Boer et al. hep-ph/ ph/ Supersymmetry: MSSM Lightest neutralino χ 0 m χ GeV S=½ Majorana particles χ 0 χ 0 > p, pbar, e +, e, γ γ pbars 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 e + Igor V. Moskalenko/NASA-GSFC 25 GLAST meeting/slac 2004/09/27-30

26 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 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 antiprotons electrons protons x4 x1.8 Igor V. Moskalenko/NASA-GSFC 26 Nuclear Data-2004/09/28, Santa Fe

27 Diffuse Gammas from Secondary Positrons/Electrons Heliosphere e + ~0.1e - e + /e sec.e - =10% Interstellar electrons Important below 200 MeV gammas e + =e - positrons Igor V. Moskalenko/NASA-GSFC 27 GLAST meeting/slac 2004/09/27-30

28 Anisotropic Inverse Compton Scattering Electrons in the halo see anisotropic radiation Observer sees mostly head-on collisions e - Energy density R=4 kpc small boost & less collisions γ head-on: large boost & more collisions e - Z, kpc γ γ high latitudes! sun Igor V. Moskalenko/NASA-GSFC 28 GLAST meeting/slac 2004/09/27-30

29 Diffuse Gammas at Different Sky Regions Hunter et al. region: l=300-60, b <10 Outer Galaxy: l=90-270, b <10 Intermediate latitudes: l=0-360,10 < b <20 Intermediate latitudes: l=0-360,20 < b <60 Igor V. Moskalenko/NASA-GSFC 29 GLAST meeting/slac 2004/09/27-30

30 Longitude Profiles b < MeV GeV 2-4 GeV 4-10 GeV Igor V. Moskalenko/NASA-GSFC 30 GLAST meeting/slac 2004/09/27-30

31 Latitude Profiles: Inner Galaxy MeV GeV 2-4 GeV 4-10 GeV GeV Igor V. Moskalenko/NASA-GSFC 31 GLAST meeting/slac 2004/09/27-30

32 Latitude Profiles: Outer Galaxy MeV GeV 2-4 GeV 4-10 GeV Igor V. Moskalenko/NASA-GSFC 32 GLAST meeting/slac 2004/09/27-30

33 Extragalactic Gamma-Ray Background Predicted vs. observed E 2 xf Sreekumar et al Elsaesser & Mannheim, astro-ph/ Strong et al E, MeV Blazars Cosmological neutralinos Igor V. Moskalenko/NASA-GSFC 33 GLAST meeting/slac 2004/09/27-30

34 Distribution of CR Sources & Gradient in the CO/H 2 CR distribution from diffuse gammas (Strong & Mattox 1996) SNR distribution (Case & Bhattacharya 1998) Pulsar distribution (Lorimer 2004) sun X CO =N(H 2 )/W CO : Histo This work, Strong et al Sodroski et al. 95, x Strong & Mattox 96 ~Z -1 Boselli et al. 02 ~Z Israel 97, 00, [O/H]=0.04,0.07 dex/kpc Igor V. Moskalenko/NASA-GSFC 34 GLAST meeting/slac 2004/09/27-30

35 Again Diffuse Galactic Gamma Rays Very good agreement! More IC in the GC better agreement! The pulsar distribution vs. R falls too fast OR larger H 2 /CO gradient Igor V. Moskalenko/NASA-GSFC 35 GLAST meeting/slac 2004/09/27-30

36 Conclusions I Accurate measurements of diffuse gamma rays, secondary antiprotons, and other CR species 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 Hunter et al. region: l=300-60, b <10 Dark Matter B/C Z h increase Be 10 /Be 9 CR species: New measurements at LE & HE simultaneously are highly desirable (Pamela, S-TIGER, AMS ), sec. positrons! Igor V. Moskalenko/NASA-GSFC 36 GLAST meeting/slac 2004/09/27-30

37 Conclusions II Antiprotons: Pamela (2005), AMS (2008) and a new BESS-polar instrument to fly a longduration 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 Igor V. Moskalenko/NASA-GSFC 37 GLAST meeting/slac 2004/09/27-30

38 Thank you! Igor V. Moskalenko/NASA-GSFC 38 GLAST meeting/slac 2004/09/27-30