GALPROP: under the hood

1
GALPROPunder the hood
Igor V. Moskalenko (stanford/kipac)
IAS, Princeton/Apr.23, 2009
2
GALPROP on the Web

• A de-facto standard in astrophysics of CRs,
  diffuse gamma rays, and indirect DM searches
  (Blasi 2007 ICRC rapporteur talk)
• The diffuse emission model has become a baseline
  for the Fermi/LAT
• Freely distributed easy access for the forefront
  science
• GALPROP cosmic gives gt5000 hits on GOOGLE
• Forum topic are visited gt60000 times since it was
  opened in 2006
• The principle authors have written 50 reviews
  and refereed papers based on its results (highly
  cited)
• Consistent funding from NASA since 2001 through
  2012 _at_ 160k/year (ATP and APRA programs, PI
  IM) funding of the proposals which use GALPROP
  

3
All Particle CR Spectrum

• This is an astonishing observation!
• All particle CR spectrum is almost featureless
• the knee
• the ankle
• GZK cutoff
• These are the only features in gt12 decades in
  energy and gt32 decades in intensity!
• However, there is a lot of information hidden in
  the spectra and abundances of individual CR
  species nuclear isotopes, antiprotons,
  electrons, positrons (diffuse gamma rays)
• CRs are the only probes of the interstellar
  material available to us.
• The whole physics is involved various branches
  of Astrophysics, MHD, shock waves, plasma
  physics, atomic, nuclear, particle physics,
  exotic physics SUSY

Galactic
Galacticextragalactic
GZK cutoff?
extragalactic
4
CR Propagation Milky Way Galaxy
1 pc 3x1018 cm
Optical image Cheng et al. 1992, Brinkman et al.
1993 Radio contours Condon et al. 1998 AJ 115,
1693
100 pc
NGC891
40 kpc
0.1-0.01/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)
5
CR Interactions in the Interstellar Medium
ISM
X,?
synchrotron
IC
ISRF
P He CNO
diffusion energy losses
reacceleration convection
production of secondaries
bremss
p
Flux
LiBeB
He CNO
20 GeV/n
BESS

• CR species
• Only 1 location
• modulation

PAMELA
ACE
helio-modulation
6
Elemental Abundances CR vs. Solar System
CR abundances ACE
output
O
Si
C
Na
Fe
S
CNO
Al
CrMn
Cl
LiBeB
F
ScTiV
Solar system abundances
input
7
Cosmic Rays vs Diffuse Gamma Rays
Even an unrealistic model (e.g. Leaky-Box) can be
fitted to the CR data, but diffuse emission
requires the CR spectra in the whole Galaxy
8
A Model of CR Propagation in the Galaxy

• Gas distribution (energy losses, p0, brems)
• Interstellar radiation field (IC, e energy
  losses)
• Energy losses ionization, Coulomb, brems, IC,
  synch
• Nuclear particle production cross sections
• Solve transport equations for all CR species
• Fix propagation parameters
• Gamma-ray production brems, IC, p0
• Precise Astrophysics

9
Components of the ISM Views from the Inside
synchrotron 21 cm H I 2.6 mm CO (H2) dust stars
star forming optical n-stars, BHs CRs x gas
10
CO maps

• Extend CO surveys to high latitudes
• newly-found small molecular clouds will otherwise
  be interpreted as unidentified sources, and
  clearly limit dark matter studies
• C18O observations (optically thin tracer) of
  special directions (e.g. Galactic center, arm
  tangents)
• assess whether velocity crowding is affecting
  calculations of molecular column density, and for
  carefully pinning down the diffuse emission

Dame, Hartmann, Thaddeus (2001) Dame Thaddeus
(2004)
11
Gas distribution in the Milky Way
Molecular hydrogen H2 is traced using J1-0
transition of 12CO, concentrated mostly in the
plane (z70 pc, Rlt10 kpc) Atomic
hydrogen H I has a wider distribution
(z1 kpc, R30 kpc) Ionized hydrogen H II
small proportion, but exists even in halo (z1
kpc)
Sun
12
Distribution of interstellar gas

• Neutral interstellar medium most of the
  interstellar gas mass
• 21-cm H I 2.6-mm CO (surrogate for H2)
• Differential rotation of the Milky Way plus
  random motions, streaming, and internal velocity
  dispersions is largely responsible for the
  spectrum
• Rotation curveV(R) ? unique line-of-sight
  velocity-Galactocentric distance relationship

CO
Rotation Curve
Dame et al. (2001)
H I
Clemens (1985)
Kalberla et al. (2005)
W. Keel
13
Problems to deal with

• H2 gas
• The conversion factor XN(H2)/WCO is unknown,
  most probably variable, and is determined from
  the diffuse ?-ray emission itself
• HI gas
• Spin temperature is unknown, it can significantly
  vary usually used the same temperature 125K for
  HI gas for the whole Galaxy
• Self absorption (cold gas cloud in front of the
  emitting cloud) the optical depth is very large

14
More on gas in the Milky Way
Surface mass density of the H2 in M sun pc-2
25
G.C.

• Problems
• Near-far ambiguity
• No velocity information in the Center-Anticenter
  direction

Pohl08
15
Dealing with neutral gas galactocentric rings
25
G.C.
sum

• Examples of the Galactocentric rings

sum
16
Central Molecular Zone
Feriere07
17
Inner 3 kpc
18
GALPROPunder the hoodPart II
Igor V. Moskalenko (stanford/kipac)
IAS, Princeton/Apr.23, 2009
19
ISRF Large Scale Distribution

• Requires extensive modeling
• Distribution of stars of different stellar
  classes in the Galaxy
• Dust emission
• Radiative transfer
• The z scale height is large, takes 10s of kpc at
  R 0 kpc to get to level of CMB

Total
Optical
IR
CMB
R 0,4,8,12,16 kpc
Energy Density
Optical IR (no CMB)
20
ISRF Angular distribution

• Calculation
• Calculate intensity maps throughout Galaxy
• stellar component
• dust component
• radiative transfer
• These vary with position AND wavelength
• Different from local intensity distribution
• Isotropic approximation for anything but CMB is
  clearly incorrect

Porter Strong
21
HESS Observations of Composite SNR G0.90.1
leptonic scenario
SNR at the GC age a few kyr
K-N cutoff
electron index d2.8
photon index 2.400.110.20
Porter,IVM,Strong06 IVM,Porter,Strong06

• Interstellar radiation field in the inner Galaxy
  is dominated by the dust (IR) emission and
  starlight

22
Nuclear Reaction NetworkCross Sections

• Many different isotopes are produced via
  spallations of CR nuclei A(p,He)?BX

stable isotopes
Secondary, radioactive 1 Myr K-capture isotopes
Co57
Fe55
Mn54
Cr51
V49
Ca41
Ar37
Cl36
ß-, n
Al26
p,EC,ß
Be7 Be10
p
Plus some dozens of more complicated
reactions But many cross sections are not well
known
n
23
Effect of Cross Sections Radioactive Secondaries
Different size from different ratios
T1/2?
Zhalo,kpc

• Errors in CR measurements (HE LE)
• Errors in production cross sections
• Errors in the lifetime estimates

24
Nuclear Reaction Network
I
II
III
IV
V
nuc_package.cc
25
nuc_package.cc Long-Lived Isotopes
Half-life for bare nucleus Half-life for H-like
atoms
26
Total Nuclear Cross Sections
Ekin, MeV/nucleon
Wellisch Axen 1996
27
Fe p data vs phenomenology
Large deviations everywhere!

• Villagrasa05

28
Fe p data vs codes

• Very large deviations at low energies!

Villagrasa05
29
LiBeB Major Production Channels

• Well defined (65)
• C12, O16 -gtLiBeB
• N14 -gt Be7
• (IVM Mashnik 2003)
• Few measurements
• C13,N -gt LiBeB
• B -gt BeB
• Unknown
• LiBeB,C13,N -gt LiBeB
• Tertiary reactions also important! -35

Propagated Abundance Cross-section
O
Li6
C
16
12
Li
B
N
Be
7
13
A
10
9
15
14
11
30
Dealing with isotopic production Xsections

• Use data where possible
• Not much data use data in conjunction with the
  results of a proper nuclear code
• Not much data, no code use Webber or ST
  semi-empirical systematics renormalized to the
  data
• Nothing available use Webber or ST
  semi-empirical systematics

31
Isotopic Production Cross Sections of LiBeB

• Semi-empirical systematics 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 cant be done without modern nuclear codes.
• Use LANL nuclear database and modern computer
  codes.

IVM Mashnik 2003
32
isotope_cs_eval.dat
33
Fitting the CR Abundances with GALPROP
Initial abundances, e.g., solar isotopic
abundances
Fine adjustment of the source abundances NSAOSA
d(ACE-propagated)
Propagation (GALPROP) 64Ni 1H
NSAnew source abundance OSAold source
abundance d0.01-0.001
Propagation parameters
Comparison with ACE data
Solar modulation (force-field)
Diffuse gammas
34
CR source isotopic abundances

• Two K-capture isotopes are present in the
  sources! -- 41Ca, 53Mn
• Could tell us about the origin of CRs -- supports
  volatility hypothesis, but needs more analysis

Solar system Reacceleration Plain diffusion
IVM,Strong,Porter07

• The first time that a realistic propagation model
  has been used to derive isotopic source
  abundances !

35
SNR distribution



Milky Way
36
Distribution of CR Sources Gradient in the CO/H2
Pulsar distribution Lorimer 2004
CR distribution from diffuse gammas (Strong
Mattox 1996) SNR distribution (Case
Bhattacharya 1998)
sun
XCON(H2)/WCO Histo This work, Strong et
al.04 ----- -Sodroski et al.95,97 1.9x1020
-Strong Mattox96 Z-1 Boselli et
al.02 Z-2.5 -Israel97,00, O/H0.04,0.07
dex/kpc
37
Galactic magnetic field
Regular B-field large-scale structure
in the plane
in the halo
Han08
synchrotron emission

• Plane bisymmetrical field with reversals on
  arm-interarm boundaries
• Halo azimuth B-fields with reversed directions
  below and above the plane
• Random field Regular field
• Consistent with observations of the synchrotron
  emission

38
Transport Equation
39
Transport Equations 90 (no. of CR species)
sources (SNR, nuclear reactions)
diffusion
convection (Galactic wind)
diffusive reacceleration (diffusion in the
momentum space)
E-loss
radioactive decay
fragmentation

• ?(r,p,t) density per total momentum

boundary conditions
40
Simplified equation VHE electrons
Simplified eq.
Cylindrically symmetric solution
2p
Bessel fns
hypergeometric fn
dhalo size aradius

• Bulanov Dogiel1974

zeros of J0
41
Electron propagation solutions
Galactic disk with sources
Galactic halo boundary
N
no energy losses
large energy losses
N0
The Galaxy
42
Analytical vs. Numerical solution

• Analytical solutions for simple cases give
  insight into the relations between the quantities
  involved and are useful for rough estimates, but
  in real cases the analytical formulae may become
  too complicated so no insight is gained
• Electrons and positrons are beyond the analytical
  methods because their energy losses are spatially
  dependent and different processes are important
  in different energy ranges
• Numerical solutions are fast and more realistic
• It is unclear whether one would wish to go much
  beyond the generalizations discussed above for an
  analytically soluble diffusion model. The added
  insight from any analytic solution over a purely
  numerical approach is quickly cancelled by the
  growing complexity of the formulae. With rapidly
  developing computational capabilities, one could
  profitably employ numerical solutions
  J.M.Wallace 1981

43
GALPROPunder the hoodPart III
Igor V. Moskalenko (stanford/kipac)
IAS, Princeton/Apr.23, 2009
44
Analytical vs. Numerical solution

• Analytical solutions for simple cases give
  insight into the relations between the quantities
  involved and are useful for rough estimates, but
  in real cases the analytical formulae may become
  too complicated so no insight is gained
• Electrons and positrons are beyond the analytical
  methods because their energy losses are spatially
  dependent and different processes are important
  in different energy ranges
• Numerical solutions are fast and more realistic
• It is unclear whether one would wish to go much
  beyond the generalizations discussed above for an
  analytically soluble diffusion model. The added
  insight from any analytic solution over a purely
  numerical approach is quickly cancelled by the
  growing complexity of the formulae. With rapidly
  developing computational capabilities, one could
  profitably employ numerical solutions
  J.M.Wallace 1981

45
Finite Differencing
46
Finite Differencing Example
47
Tri-Diagonal Matrix
48
Coefficients for the Crank-Nicholson Method
49
Spatial Grids

• Typical grid steps (can be arbitrary!)
• ?z 0.1 kpc, ??z 0.01 kpc (gas averaging)
• ?R 1 kpc
• ?E x1.2 (log-grid)

50
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 p0-decay, IC, bremsstrahlung
• Emissivities in every grid point
  (x,y,R,z,E,process)
• Skymaps with a given resolution (l,b,E,process)
• Output of maps separated into HI, H2, and rings
  to allow fitting X-factors, CR source
  distribution etc.

51
How It Is Done Secondary Particles

• Positrons/electrons pp-gtp,K-gte (MS 1998)
• Dermer 1986 method LE Stecker ?-isobar model
  (isotropic decay), HE scaling (inv. x-section
  Stephens Badhwar 1981), plus interpolation in
  between
• Pion decay includes polarization of muons
• Kaon decay scaling (Stephens Badhwar 1981)
• Kamae et al. formalism
• Antiprotons (IM02)
• pp inclusive production x-section (Tan Ng 1983)
• pA, AA-gt pbar scaling using Gaisser Schaeffer
  1992 or Simon et al. 1998 results similar (Mori
  coeff. will be implemented)
• Total inelastic x-section (p TN83, A Moiseev
  Ormes 1997)
• ppbar annihilation x-section (ppbar)tot
  (pp)tot (LE TN83, HE PDG00 Regge
  parameterization)

52
How It Is Done Nucleons

• Calculated for pA reactions and scaled for aA
  (Ferrando et al. 1988)
• Calculation of total nuclear cross sections
• Letaw et al. 1983
• Wellisch Axen 1996 (corrected), Zgt5
• Barashenkov Polanski 2001
• Calculation of isotopic production cross sections
• Webber et al. 1993 (non-renormalized,
  renormalized) Egt200 MeV/nucleon, essentially
  flat
• Silberberg Tsao 2000 (non-renormalized,
  renormalized) claim that it works at all
  energies, but is problematic sometimes
• Fits to the available data (LANL, Webber et al.,
  etc.) in the form of a function or a table (see
  .dat files), but data may not be always available
• Use the best of all three, but very time
  consuming work
• Nuclear reaction network
• Nuclear Data Tables (includes several decay
  channels branching)
• Standard ß -decay, emission of p, n
• K-capture isotopes are treated separately

53
How It Is Done Gammas

• Bremsstrahlung (Koch Motz 1959, SMR2000) many
  different regimes
• LE 0.01 lt Ekin lt 0.07 MeV nonrelativistic
  non-screened brems
• Intermediate 0.07 lt Ekin lt2 MeV
• HE Ekin gt 2 MeV arbitrary screening unshielded
  charge, 1-, 2-electron atoms (form factors,
  Hylleraas, Hertree-Fock wave functions)
• Fano-Sauter limit k-gtEkin
• Anisotropic IC (MS2000)
• Takes into account the anisotropic angular
  distribution of background photons
• Troy is working on new faster implementation
• Neutral pion decay (see secondary
  positrons/electrons)
• Synchrotron radiation (Ginzburg 1979, Ghisellini
  et al. 1988)
• Averaging over pitch angle
• Uses total magnetic field (regular random)
• Emissivities uses real H2, H I gas column
  densities (rings)
• Skymap calculations integration over the line of
  sight

54

• Propagation in the interstellar medium

55
Secondary/Primary Ratio

• Leaky-box model
• fitting path-length distribution -gt free
  function

• Diffusion models
• Diffusive reacceleration
• Convection
• Damping of interstellar turbulence
• Etc.

B/C
Ek, MeV/nucleon
Accurate measurements in a wide energy range may
help to distinguish between the models
56
if the mirror is moving towards the incident
particle, the particle gains energy upon
reflection, just as does a tennis ball pushed by
a racket
57
Distributed Stochastic Reacceleration
Scattering on magnetic turbulences
Simon et al. 1986 Seo Ptuskin 1994
Dpp p2Va2/D D vR1/3 - Kolmogorov spectrum
Icr
1/3
?E
strong reacceleration

• Fermi 2-nd order mechanism

weak reacceleration
Dxx 5.2x1028 (R/3 GV)1/3cm-2 s-1 Va 36 km
s-1 ? R-d, d1.8/2.4 below/above 4 GV
E
58
Diffusion in Galactic magnetic fields
Magnetic turbulences random field
inhomogeneities random walk
59
Convection
Galactic wind
Jones 1979
DR0.6

• Escape length

Xe
v
R-0.6
wind or turbulent diffusion
resonant diffusion
E
problem too broad sec/prim peak
Dxx 2.5x1028 (R/4 GV)0.6cm-2 s-1 dV/dz 10 km
s-1 kpc-1 ? R-d, d2.46/2.16 below/above 20 GV
60
Damping of Interstellar Turbulence
Kolmogorov cascade
Iroshnikov-Kraichnan cascade
nonlinear cascade
W(k)

• Simplified case
• 1-D diffusion
• No energy losses

dissipation
k
Mean free path
1/1020cm
1/1012cm
Ptuskin2003, 2005
61
Dxx Diffusion Coefficient
R0.6
Reacceleration with damping
Plain diffusion
ß-3
Diffusive reacceleration
62
Fixing Propagation Parameters
Radioactive isotopes Galactic halo size Zh
E2 Flux
B/C
Carbon
Be10/Be9
Interstellar
Ek, GeV/nucleon
Ek, MeV/nucleon
Zh increase

• Using secondary/primary nuclei ratio flux
• Diffusion coefficient and its index
• Propagation mode and its parameters (e.g.,
  reacceleration VA, convection Vz)
• Propagation params are model-dependent
• Make sure that the spectrum is fitted as well

Ek, MeV/nucleon
Parameters (model dependent) D 1028 (?/1 GV)a
cm2/s a 0.3-0.6 Zh 4-6 kpc VA 30 km/s
63
Secondary/Primary Nuclei Ratio
B/C
B/C
CREAM Ahn08
Jones01
Sub-Fe/Fe

• Secondary/primary nuclei ratio in CR is declining
  gt1 GeV/n, not rising!

64
B/C ratio _at_ HE

• Different propagation models are tuned to fit the
  low energy part of sec./prim. ratio where the
  accurate data exist

ACE Ulysses Voyagers
Jones01
Reacceleration
CREAM Ahn08
Standard diffusion

• However, they differ at high energies which will
  allow to discriminate between them when more
  accurate data will be available

65
Effect of Cross Sections Radioactive Secondaries
Different size from different ratios
T1/2?
Zhalo,kpc

• Errors in CR measurements (HE LE)
• Errors in production cross sections
• Errors in the lifetime estimates

66
Light isotopes

• Light isotopes are produced mostly by the
  CNO-nuclei (but tertiary component from LiBeB is
  also important) relatively easy to calculate,
  but there is no much data above 1 GeV/n
• Also provide constraints on the propagation models

de Nolfo06
67
Fitting the CR Abundances with GALPROP
Initial abundances, e.g., solar isotopic
abundances
Fine adjustment of the source abundances NSAOSA
d(ACE-propagated)
Propagation (GALPROP) 64Ni 1H
NSAnew source abundance OSAold source
abundance d0.01-0.001
Propagation parameters
Comparison with ACE data
Solar modulation (force-field)
Diffuse gammas
68
CR source isotopic abundances

• Two K-capture isotopes are present in the
  sources! -- 41Ca, 53Mn
• Could tell us about the origin of CRs -- supports
  volatility hypothesis, but needs more analysis

Solar system Reacceleration Plain diffusion
IVM,Strong,Porter07

• The first time that a realistic propagation model
  has been used to derive isotopic source
  abundances !

69
Pamela positron fraction

• Excess in positron fraction is confirmed and
  extended to higher energies

sec. production (GALPROP)
Solar modulation
Adriani08 (arXiv0810.4995)
70
Fermi LAT ee- spectrum

• no prominent spectral features between 20 GeV
  and 1 TeV
• significantly harder spectrum than inferred from
  previous measurements

• events for e e- analysis required to fail ACD
  vetoes for selecting g events resulting g
  contamination lt 1
• further cuts distinguish EM and hadron events
  rejection 1103 up to 200 GeV 1104 at 1 TeV
• energy reconstruction aided by shower imaging
  capability of calorimeter
• more than 4x106 e-e events in selected sample
• Simple normalized E-3.04 power law fits the Fermi
  data reasonably well (c2 9.7, d.o.f. 24,
  including estimated systematic uncertainties)

71
HESS electron (photon) spectrum
HESS

• Sharp cutoff at 1 TeV
• No strong local sources?
• Features at higher energies?

72
Pamela pbar/p ratio

• Pbar/p ratio is consistent with secondary origin

GALPROP
Adriani08 (arXiv0810.4994)
73
Pamela pbars

• Absolute pbar flux is consistent with secondary
  origin

From M.Boezio talk at SLAC
74
Fermi/LAT First 3 months rate skymap
75
Diffuse emission at mid-latitudes
sin 100.17 ZH2 50 pc sin 200.34 vs ZHI
400 pc

• Conventional GALPROP model is in agreement with
  the LAT data at mid-latitudes (mostly local
  emission)

76
Morphology of the Diffuse Emission _at_ 150 GeV
IC
p0

• Conventional
• Dark Matter

RegisUllio09
IC
p0
77
Milagro Skymap

• 34 Fermi BSL Galactic sources above declination
  of -5o
• 14 detected by Milagro above 3s
• FDR Miller 2001 estimates 1 false positive rate
• 5 new TeV sources
• Geminga 6.3s as extended source (2.6o fwhm)

Credit G.Sinnis
78
Milagro TeV Observations of Fermi Sources
unID (new TeV source) Fermi Pulsar MGRO
190806 HESS 1908063
IC433 SNR MAGIC VERITAS
Geminga Pulsar Milagro C3
Radio pulsar J063110 (new TeV source)
unID (new TeV source)
Pulsar (AGILE/Fermi) MGRO 201937
Fermi Pulsar g Cygni SNR Fermi Pulsar HESS
203241 MGRO 203141 MAGIC 20324130
Fermi Pulsar Milagro (C4) 3EG 22276122 Boomerang
PWN
G65.10.6 (SNR) Fermi Pulsar (J1958) New TeV
sources
W51 HESS J1923141 SNR
Credit G.Sinnis
79
Anisotropic Inverse Compton Scattering

• Electrons in the halo see anisotropic radiation
• Observer sees mostly head-on collisions

Energy density
e-
R4 kpc
small boost less collisions
e-
head-on large boost more collisions
Z, kpc
?
?
?
Important _at_ high latitudes !
sun
80
Effect of anisotropic ICS
Ratio anisoIC/isoIC
pole
anti-GC
Intermediate latitudes
GC

• The anisotropic IC scattering plays important
  role in modeling the Galactic diffuse emission
• Affects estimates of isotropic extragalactic
  background

Galactic latitude, degrees
81
Extragalactic Gamma-Ray Background
EGRB in different directions
Predicted vs. observed
E2xF
Sreekumar et al. 1998
Elsaesser Mannheim05
Strong et al. 2004
E, MeV

• Blazars
• Cosmological neutralinos

82
(No Transcript)
83
Contributions to the extragalactic background
?gt100!
Dermer07
84
First 3 months of LAT data
PSR J18365925
3C 454.3
PKS 1502106
85
(Some) Important Questions to Answer

• How large is the positron fraction at HE (PAMELA)
• Identifies the nature of sources of primary
  positrons
• If SNRs are the sources of primary positrons,
  this should also affect secondary nuclei
• Measure the secondary nuclei (PAMELA, CREAM)
• How typical for the local Galactic environment is
  the observed Fermi/LAT spectrum
• If this is the typical spectrum than the sources
  of primary positrons are distributed in the
  Galaxy (could be pulsars, SNRs, or DM)
• If this spectrum is peculiar than there is a
  local source or sources of primary positrons
• The answer is in the diffuse gamma-ray emission
  (Fermi/LAT)
• Dark matter vs Astrophysical source
• Distribution of the IC emission at HE (Fermi/LAT)
• WE HAVE ALL NECESSARY INSTRUMENTS IN PLACE (in
  the orbit) TO ANSWER THESE QUESTIONS

86
More data expected!

• ATIC and CREAM
• Elemental abundances up to 1015 eV
• PAMELA
• Absolute positron flux
• More on absolute antiproton flux
• Electrons
• Light nuclei
• Fermi Large Area Telescope
• Electrons gt1 TeV
• Diffuse emission (Galactic and extragalactic)
• Keep tuned
• A probe of the CR electron spectrum from the
  solar surface to Saturns orbit at 10 AU
• A probe of the local interstellar CR proton
  spectrum
• AMS will it fly in 2010?