Igor V. Moskalenko NASA Goddard Space Flight Center [email protected] with Andy W....

Igor V. MoskalenkoIgor V. MoskalenkoNASA Goddard Space Flight Center

[email protected]

withAndy W. StrongAndy W. Strong (MPE, Germany) & Stepan G. MashnikStepan G. Mashnik

(LANL)

Propagation of Cosmic Rays and Propagation of Cosmic Rays and

Diffuse Galactic Gamma RaysDiffuse Galactic Gamma Rays(nuclear physics in cosmic ray studies)(nuclear physics in cosmic ray studies)

Igor V. Moskalenko/NASA-GSFC 2 Nuclear Data-2004/09/26-10/1 Santa Fe, NM

All Particle CR Spectrum

Energetically SNR – most probable sources of CR: ~5x1049 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 notprotons…


EGRET Sky: “GeV Excess”

The diffuse The diffuse γγ-ray emission is the -ray emission is the dominant feature of the dominant feature of the γγ-ray sky – -ray sky – an evidence of CR interactions in the an evidence of CR interactions in the interstellar medium: interstellar medium: bremsstrahlung, IC, bremsstrahlung, IC, ππ00

Hunter et al. 1997

Excess


Reacceleration Model: Secondary Reacceleration Model: Secondary PbarsPbars

B/C ratio Antiproton flux

Ek, GeV/nucleon

Ek, GeV


Positron Excess ?

Are all the excesses Are all the excesses connected connected somehow ?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 E-losses -> Large E-losses ->

local spectrum…local spectrum…

HEAT (Coutu et al. 1999)

Leaky-Box

GALPROP

e+/e

E, GeV

1 10

100


Propagation of Cosmic Rays: Why?Propagation of Cosmic Rays: Why?

ModelingModeling of the CR propagation and diffuse of the CR propagation and diffuse gamma-ray emission gamma-ray emission requiresrequires to combine to combine many many different kinds of datadifferent kinds of data obtained from obtained from astrophysical observations, and nuclear and astrophysical observations, and nuclear and particle physics experiments.particle physics experiments.

Why Do We Need to Study CR Propagation ?Why Do We Need to Study CR Propagation ?

In returnIn return, a correct model provides a basis for , a correct model provides a basis for many studies in Astrophysics, Particle Physics, many studies in Astrophysics, Particle Physics, and Cosmologyand Cosmology


Dark Matter Signatures in CR

Diffuse gammas Antiprotons

Ek, GeVE, GeV

Well... But where is the nuclear physics?!


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~3x1018 cm

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

Optical image: Cheng et al. 1992, Brinkman et al. 1993Radio contours: Condon et al. 1998 AJ 115, 1693

NGC891

Sun


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

diffusion energy losses reacceleration convection etc. π0

synchrotron

synchrotron

IC

bremss

Chandra

GLAST

ACE

BESS

Halo

disk

escape

HeCNOsolar

modulation

AMS

p


Heliosphere

Flux

20 GeV/n


Transport EquationTransport Equation

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

df

Vpdt

dp

p

ppppDp

p

Vxx

D

prqt

tpr

3

1

22

][

),(),,(

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

convectionconvectiondiffusiondiffusion

diffusive reaccelerationdiffusive reacceleration

E-lossE-loss convectionconvection

fragmentationfragmentation radioactive decayradioactive decay


Elemental Abundances: CR vs. Solar System

CR abundances: ACE

Solar system abundances

LiBeB

CNO

F

Fe

ScTiV

CrMn

Si

Cl

Al

O

Na

S


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 (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

Extragalacticdiffuse γ-

rays: blazars, relic

neutralino

Dark Matter (p,đ,e+,γ)-


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)

Radioactive isotopes:

Galactic halo size Zh Zh increase

B/C

Be10/Be9

Inte

rste

llar

Ek, MeV/nucleon

Ek, MeV/nucleon


stripping

5151CrCrattachment

Tim

e s

cale

(years

)

EC decay

Ek, MeV/nucleon

K-capture isotopes

Niebur et al. 2003

5151V/V/5151CrCr

Ek, MeV/nucleon

5151V/V/5151Cr Cr ≡ daughter/parent≡ daughter/parentElectron attachment & stripping

Solar modulation effect

Jones et al. 2001

5151V/V/5151CrCr

Ek, MeV/nucleon

K-capture & reacceleration

ISM


First Ionization Potential (FIP) vs. Volatility

•Low-FIP ~ Refractories•Rb, Cs – break the rule•Other important elements: Na, Cu, Zn, Ga, Ge, Pb

Rb

CsK

Pb

GeGa

Na

Zn

Se

Cu

~104 K


Effect of Cross Sections: Radioactive Effect of Cross Sections: Radioactive SecondariesSecondaries

Different Different size from different ratios…size from different ratios…

Zhalo,kpc

STST

WW

2727Al+pAl+p2626AlAl

•ErrorsErrors in CR measurements (HE & LE) in CR measurements (HE & LE)•ErrorsErrors in production cross sections in production cross sections•ErrorsErrors in the lifetime estimates in the lifetime estimates•DifferentDifferent origin of elements (Local origin of elements (Local Bubble ?)Bubble ?)

natnatSi+pSi+p2626AlAl

WW

STST

TT1/21/2==??

Ek, MeV/nucleon


Bigger picture…


Matter, Dark Matter, Dark Energy…

Ω ≡ ρ/ρcrit

Ωtot =1.02 +/−0.02

ΩMatter =4.4%+/−0.4%

ΩDM =23% +/−4%

ΩVacuum =73% +/−4%

Dark Energy

Dark Matter

Visible atoms

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…


Example “Global Fit:” diffuse Example “Global Fit:” diffuse γγ’s, pbars, ’s, pbars, positrons 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+

γ

GALPROP/W. de Boer et al. hep-ph/0309029GALPROP/W. de Boer et al. hep-ph/0309029

Supersymmetry: MSSM Lightest neutralino χ0

mχ ≈ 100-500 GeV S=½ Majorana

particles χ0χ0−> p, pbar, e+,

e−, γ


CR Fluctuations/SNR stochastic eventsCR Fluctuations/SNR stochastic events

GeV electronsGeV electrons 100 TeV electrons100 TeV electronsGALPROP/Credit S.Swordy

Electron energy lossesElectron energy losses

107 yr

106 yr

BremsstrahlungBremsstrahlung

1 TeV

IonizationIonization

CoulombCoulomb IC, synchrotronIC, synchrotron

1 GeV

Ekin, GeVEkin, GeV

E(d

E/d

t)E(d

E/d

t)-1-1,y

r,y

r

Historical variations Historical variations of CR of CR intensity over intensity over 150 000150 000 yr yr (Be(Be1010 in South Polar ice) in South Polar ice)

Konstantinov et al. 1990

Igor V. Moskalenko/NASA-GSFC 22 Nuclear Data-2004/09/28, Santa Fe

GeV excess: Optimized model

Uses Uses all skyall sky and antiprotons & gammas and antiprotons & gammas to fix the nucleon and electron spectrato fix the nucleon and electron spectra

Uses Uses antiprotonsantiprotons to fix to fix the the intensityintensity of CR nucleons @ HE of CR nucleons @ HE

Uses Uses gammasgammas to adjust to adjust the nucleon spectrum at LEthe nucleon spectrum at LE the the intensity intensity of the CR electrons of the CR electrons (uses also synchrotron index)(uses also synchrotron index)

Uses EGRET data Uses EGRET data up to 100 GeVup to 100 GeV

protonsprotonselectronselectrons

x4x4

x1.8

antiprotonsantiprotons

EEkk, GeV, GeV

EEkk, GeV, GeV

EEkk, GeV, GeV


Longitude Profiles |b|<5°

50-70 MeV

2-4 GeV

0.5-1 GeV

4-10 GeV


Extragalactic Gamma-Ray Background

Predicted vs. observedPredicted vs. observed

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

E, GeVE, GeV


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

Zh increase

Be10/Be9

EEkk, MeV/nucleon, MeV/nucleon

B/C

EEkk, MeV/nucleon, MeV/nucleon


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


Thank you !

Igor V. Moskalenko NASA Goddard Space Flight Center [email protected] with Andy W....

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