1. Isotopic abundances of CR sources
Igor V. Moskalenko (Stanford)
Andrew W. Strong (MPE)
Troy A. Porter (UCSC)

2. CR Interactions in the Interstellar Medium
42 sigma ( data)
HESS
SNR RX J
PSF
ISM
X,γ e + -
synchrotron
Chandra B IC P He
CNO
ISRF
diffusion
energy losses
reacceleration
convection
etc.
bremss
gas e + - π π + -
GLAST
gas P _ π + - p
LiBeB
Flux He
CNO e + -
20 GeV/n
BESS
CR species:
Only 1 location
modulation
PAMELA
ACE
helio-modulation

3. CR Propagation: Milky Way Galaxy
1 kpc ~ 3x1018 cm
Optical image: Cheng et al. 1992, Brinkman et al. 1993
Radio contours: Condon et al AJ 115, 1693
NGC891
100 pc
Halo
Gas, sources
40 kpc
/ccm
1-100/ccm
Sun
4-12 kpc
Intergalactic space
R Band image of NGC891
1.4 GHz continuum (NVSS), 1,2,…64 mJy/ beam
“Flat halo” model (Ginzburg & Ptuskin 1976)

4. A Model of CR Propagation in the Galaxy
Gas distribution (energy losses, π0, brems)
Interstellar radiation field (IC, e± energy losses)
Nuclear & particle production cross sections
Transport equations for all CR species (H-Ni, pbars, e±)
Energy losses: ionization, Coulomb, brems, IC, synch
Fix propagation parameters
Gamma-ray production: brems, IC, π0; synchrotron
Astrophysics

5. Transport Equations ~90 (no. of CR species)
sources (SNR, nuclear reactions…)
diffusion
convection (Galactic wind)
diffusive reacceleration (diffusion in the momentum space)
E-loss
fragmentation
radioactive decay
ψ(r,p,t) – density per total momentum
+ boundary conditions

6. Column densities of gas
Here are examples of the resulting ‘rings’
For the local ( kpc) annulus we are incorporating new intermediate latitude CO survey data (Dame 2007) and additional coverage from the NANTEN survey in the south (Onishi, Mizuno, & Fukui 2004)
WCO
N(H I)

7. How It Works: Fixing Propagation Parameters
E2 Flux
B/C
Carbon
Radioactive isotopes:
Galactic halo size Zh
Interstellar
Ek, GeV/nucleon
Be10/Be9
Ek, MeV/nucleon
Using secondary/primary nuclei ratio & flux:
Diffusion coefficient and its index
Propagation mode and its parameters (e.g., reacceleration VA, convection Vz)
Zh increase
Ek, MeV/nucleon

8. ACE Isotopic Abundances vs SS Abundances
Solar System
Wiedenbeck+2001

9. Fitting procedure Solar isotopic abundances Propagation (GALPROP) 64Ni… 1H
Comparison with ACE data
Fine adjustment of the source abundances:
NSA=OSA*δ*(ACE-propagated)
Solar modulation (force-field)
Propagation parameters
NSA=new source abundance
OSA=old source abundance δ~

10. Quality of the Fit problematic Xsections F V Ti 5% Reminder:
Reacceleration
Plain diffusion Ti 5%
Reminder:
fitted are the isotopic abundances while shown are elemental abund.
Example:
Carbon: 12C is fitted well, but 13C is overproduced – Xsection problems
Accuracy: generally better than 5%

11. Source Isotopic Abundances vs SS
Solar system:
Anders & Grevesse’89
Lodders’03
Agrees remarkably well with the latest SS abundances by Lodder for many nuclei!

12. Detailed comparison 20Ne 32S 53Mn* 40Ca 41Ca* 22Ne P F 55Mn 15N 33S
Good
Xsections
Well-known
Differences in models
ScTiV

13. Conclusions
This is the first time that a `realistic' (i.e. full spatial- and energy-dependence) propagation model has been used to derive isotopic source abundances for a full range of nuclei
The results are encouraging!