galprop: principles, internal structure, recent results ... · pdf fileigor v. moskalenko...

Igor V. Igor V. MoskalenkoMoskalenko && Andy W. StrongAndy W. StrongNASA/GSFC NASA/GSFC MPE, GermanyMPE, Germany

withwithOlafOlaf ReimerReimer

BochumBochum, Germany, Germany

Topics to cover:Topics to cover:

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

GALPROP: principles, inputs/outputs, calculationsGALPROP: principles, inputs/outputs, calculationsRecent results (Recent results (GeVGeV excess & excess & pbarspbars, extragalactic background), extragalactic background)Dark MatterDark MatterNear future developmentsNear future developments

Igor V. Moskalenko/NASA-GSFC 2 GLAST meeting/SLAC 2004/09/27-30

Transport EquationTransport Equation

df

Vpdtdp

p

ppppDpp

VxxD

prqttpr

τψ

τψ

ψψ

ψ

ψψ

ψ

−−

⋅∇−

∂∂

−

∂∂

∂∂

+

−∇⋅∇+

=∂

∂

rr

rrr

rr

31

22

][

),(),,( sources (SNR, nuclear reactions…)sources (SNR, nuclear reactions…)

convectionconvectiondiffusiondiffusion

diffusive reaccelerationdiffusive reacceleration

EE--lossloss convectionconvection

fragmentationfragmentation radioactive decayradioactive decay

ψψ((rr,p,t),p,t) –– density per total momentum


CR Propagation: Milky Way Galaxy

Halo

Gas, sources

100 pc

40 kpc

Sun

4-12

kpc

0.1-0.01/ccm

1-100/ccm

Intergalactic space

1 kpc~3x1018 cmOptical image: Cheng et al. 1992, Brinkman et al. 1993Radio contours: Condon et al. 1998 AJ 115, 1693

R Band image of NGC8911.4 GHz continuum (NVSS), 1,2,…64 mJy/ beam

NGC891


CR Interactions in the Interstellar Medium

e+-

Sources:SNRs, Shocks,Superbubbles

Particle accelerationPhoton emission P

HeCNO

X,γ

gas

gas

B

ISRF

π

e+-

+-

P_

LiBeB

ISM

diffusionenergy losses

reaccelerationconvection

etc. π0

synchrotronsynchrotron

IC

bremss

Chandra

ACE

BESS

Halo

disk

escape

HeCNOsolar

modulation

AMS

p

GLAST


GALPROP Input: galdef-files

GALPROP is parameter-driven (user can specify everything!)Grids• 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 stepsPropagation parameters• Dxx, VA, VC & 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…


Grids

Z

R,x,y0 1 2 3 4 5 6 7

1

-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)


Gas Distribution

Sun

Molecular hydrogen H2is traced using J=1-0 transition of 12CO,concentrated mostly in the plane (z~70 pc, R<10 kpc)

Atomic hydrogen H Ihas a wider distribution (z~1 kpc, R~30 kpc)

Ionized hydrogen H II –small proportion, but exists even in halo (z~1 kpc)


Interstellar Radiation FieldEnergy density

Energy density Sun

• Stellar• Dust• CMB


Nuclear Reaction Network+Cross Sections

p,EC,p,EC,ββ++

ββ--, , nn

Be7 Be10

Al26

Cl36

Mn54

Plus some dozens of more complicated reactions.But many cross sections are not well known…

V49

Ca41

Cr51

Fe55Co57

Ar37

SecondarySecondary,,radioactive ~1 radioactive ~1 MyrMyr

& & KK--capturecapture isotopesisotopes


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 (t1/2~1 Myr): 10Be, 26Al, 36Cl, 54Mn

K-capture: 37Ar,49V, 51Cr, 55Fe, 57Co

Short t1/2 radio 14C & heavy Z>30

Heavy Z>30: Cu, Zn, Ga, Ge, Rb

Nucleo-synthesis:

supernovae,

early universe,

Big Bang…

Solar

modulation

Diffuse γ-raysGalactic,

extragalactic:blazars, relic

neutralino

Dark Matter(p,đ,e+,γ)-

Nuclear component in CR: What we can learn?


Fixing Propagation Parameters: Standard Way

Using secondary/primary nuclei ratio:•Diffusion coefficient and its index•Propagation mode and its parameters (e.g., reacceleration VA, convection Vz)

Zh increase

B/C

Be10/Be9

Inte

rste

llar

Ek, MeV/nucleon

Ek, MeV/nucleon

Radioactive isotopes:Galactic halo size Zh


Peak in the Secondary/Primary Ratio

• Leaky-box model: fitting path-length distribution -> free function

B/C

• Diffusion models:Diffusive reaccelerationConvectionDamping of interstellar turbulenceEtc.

Measuring many isotopes in CR simultaneously may help to distinguish


Heliosphere

Flux

20 GeV/n


Electron Fluctuations/SNR stochastic events

GeV electrons 100 TeV electronsGALPROP/Credit S.Swordy

Energy losses

107 yr

106 yr

Bremsstrahlung

1 TeV

Ionization

Coulomb

IC, synchrotron

1 GeV

Ekin, GeV

E(dE

/dt)

-1,y

r

Electron energy loss timescale:1 TeV: ~300 000 yr100 TeV: ~3 000 yr


CR Variations in Space & Time

More frequent SN in the spiral arms

Historical variations Historical variations of CR of CR intensity over intensity over 150 000 yr150 000 yr(Be(Be1010 in South Polar ice)in South Polar ice)

Konstantinov et al. 1990Electron/positron energy losses Different “collecting” areas A vs. p


GALPROP Output/FITS files

Provides literally everything:• All nuclei and particle spectra in every grid point

(x,y,R,z,E) -FITS filesSeparately for π0-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


algorithmnumerical solution of cosmic-ray transport2D or 3D gridtime-independent or time-dependent

primary source functions (p, He, C .... Ni)source abundances, spectraprimary propagation -starting from maxA=64

source functions (Be, B...., e+,e-, pbars)using primaries and gas distributions secondary propagation

tertiary source functionstertiary propagation

γ-rays (IC, bremsstrahlung, πo-decay) radio: synchrotron


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 optionsHeliospheric 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 stored3.With propagated spectra: calculate the emissivities (π0-decay, IC, bremss)

in every grid point4. 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


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 π0-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 stepHeliospheric modulation:• Implementing a complimentary drift model by M.PotgieterVisualization 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


Recent results


Wherever you look, the GeV γ - ray excess is there !

4a-f


Reacceleration Model: Secondary PbarsReacceleration Model: Secondary Pbars

B/C ratio

Ek, GeV/nucleon

Antiproton flux

Ek, GeV


Positron Excess ?

HEAT (Coutu et al. 1999)

Are all the excesses Are all the excesses connected somehow ?connected somehow ?A signature of a new A signature of a new physics (DM) ?physics (DM) ?

Caveats:Systematic errors ? Systematic errors ? A local source of A local source of primary positrons ?primary positrons ?Large ELarge E--losses losses --> local > local spectrum…spectrum…

Leaky-BoxGALPROP

e+/e

E, GeV1 10 100


Matter, Dark Matter, Dark Energy…

Dark Energy

Dark Matter

Visible atoms

SUSY DM candidate has also other reasons to exist -particle physics…

Ω ≡ ρ/ρcrit

Ωtot =1.02 +/−0.02ΩMatter =4.4% +/−0.4%ΩDM =23% +/−4%ΩVacuum =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)


Example “Global Fit:” diffuse γ’s, pbars, positrons GALPROP/W. de Boer et al. hepGALPROP/W. de Boer et al. hep--ph/0309029ph/0309029

pbars

e+

γ

Supersymmetry:MSSMLightest neutralino χ0

mχ ≈ 100-500 GeVS=½ Majorana particlesχ0χ0−> p, pbar, e+, e−, γ

Look at the combined (pbar,e+,γ) dataPossibility of a successful “global fit” can not be excluded -non-trivial !If successful, it may provide a strong evidence for the SUSY DM

Igor V. Moskalenko/NASA-GSFC 26 Nuclear Data-2004/09/28, Santa Fe

GeV excess: Optimized model

protons

x1.8

antiprotons

GeV excess: Optimized modelUses Uses all skyall sky and antiprotons & gammasand antiprotons & gammasto fix the nucleon and electron spectrato fix the nucleon and electron spectra

Uses antiprotons to fix the intensity of CR nucleons @ HEUses gammas to adjust

the nucleon spectrum at LEthe intensity of the CR electrons

(uses also synchrotron index)Uses EGRET data up to 100 GeV

electrons

x4x4


Diffuse Gammas from Secondary Positrons/Electrons

e+~0.1e-

e+/e

electrons

positrons

gammas

e+=e-

sec.e-=10%

Importa

nt below

200

MeV

Heliosphere Interstellar


Anisotropic Inverse Compton Scattering

Electrons in the halo see anisotropic radiationObserver sees mostly head-on collisions

e-

e-

head-on:large boost &more collisions

γγ

small boost &less collisions

γ

sun

Energy density

Z, kpc

R=4 kpc

Important @ high latitudes !


Diffuse Gammas at Different Sky RegionsDiffuse Gammas at Different Sky Regions

Hunter et al. region:l=300°-60°,|b|<10°

Intermediate latitudes:l=0°-360°,10°<|b|<20°

Outer Galaxy:l=90°-270°,|b|<10°

Intermediate latitudes:l=0°-360°,20°<|b|<60°


Longitude Profiles |b|<5Longitude Profiles |b|<5°°

50-70 MeV

2-4 GeV

0.5-1 GeV

4-10 GeV


Latitude Profiles: Inner Galaxy

50-70 MeV 2-4 GeV0.5-1 GeV

4-10 GeV 20-50 GeV


Latitude Profiles: Outer Galaxy

50-70 MeV

2-4 GeV

0.5-1 GeV

4-10 GeV


Extragalactic GammaExtragalactic Gamma--Ray BackgroundRay Background

E, MeVE, MeV

EE22xFxF

Sreekumar et al. 1998Sreekumar et al. 1998

Strong et al. 2004Strong et al. 2004Elsaesser & Mannheim,

astro-ph/0405235

• Blazars• Cosmological neutralinos

Predicted vs. observedPredicted vs. observed


Distribution of CR Sources & Gradient in the CO/H2

CR distribution from diffuse gammas (Strong & Mattox 1996)SNR distribution (Case &

Bhattacharya 1998)Pulsar distribution (Lorimer 2004)

sun

XXCOCO=N(H=N(H22)/W)/WCOCO::Histo –This work, Strong et al.’04----- -Sodroski et al.’95,’971.9x1020 -Strong & Mattox’96~Z-1 –Boselli et al.’02~Z-2.5 -Israel’97,’00, [O/H]=0.04,0.07 dex/kpc


Again Diffuse Galactic Gamma Rays

Very good agreement !Very good agreement !

More IC in the GC –better agreement !

The pulsar distribution vs. R falls too fast OR

larger H2/CO gradient


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.

Hunter et al. region:l=300°-60°,|b|<10°

Dark MatterGamma rays: GLAST is scheduled to launch in 2007 – diffuse gamma rays is one of its priority goals

B/C

Zh increase

Be10/Be9 CR species: New measurements at LE & HE simultaneously are highly desirable (Pamela, S-TIGER, AMS…), sec. positrons !


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


Thank you !

galprop: principles, internal structure, recent results ... · pdf fileigor v. moskalenko...

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