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Challenges in Astrophysics of CR (knee--) & γ -rays. Igor V. Moskalenko (Stanford U.). Topics covered: Intro to the relevant physics Modeling of the CR propagation and diffuse emission Perspectives: Pamela, GLAST and other near future missions. CR Interactions in the Interstellar Medium. - PowerPoint PPT Presentation
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Igor V. Moskalenko Igor V. Moskalenko (Stanford U.)(Stanford U.)
Challenges in AstrophysicsChallenges in Astrophysics
of CR (knee--) & of CR (knee--) & γγ-rays-rays
Topics covered: Intro to the relevant physics Modeling of the CR propagation and diffuse
emission Perspectives: Pamela, GLAST and other near
future missions
Igor V. Moskalenko 2 November 17, 2005 Miniworkshop/Rome2, Italy
CR Interactions in the Interstellar Medium
e+-
PPHeHe
CNOCNO
X,γ
gas
gas
ISRF
e+-
π+-
PP__
LiBeBLiBeB
ISM
diffusiondiffusion energy losses energy losses reaccelerationreacceleration convectionconvection etc.etc.
π0
synchrotron
IC
bremss
Chandra
GLAST
ACEhelio-modulation
pp
42 sigma (2003+2004 data)
HESS Preliminary
SNR RX J1713-3946SNR RX J1713-3946
PSF
B
HeHeCNOCNO Fl
ux
20 GeV/n
CR species: Only 1 location modulation
e+-
π+-
PAMELABESS
AMS
Igor V. Moskalenko 3 November 17, 2005 Miniworkshop/Rome2, Italy
Elemental Abundances: CR vs. Solar System
CR abundances: ACE
Solar system abundances
LiBeB
CNO
F
Fe
ScTiV
CrMn
Si
Cl
Al
O
Na
S
Long propagation history…
Igor V. Moskalenko 4 November 17, 2005 Miniworkshop/Rome2, Italy
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
Diffuse γ-raysGalactic,
extragalactic: blazars, relic
neutralino
Dark Matter (p,đ,e+,γ)-
Igor V. Moskalenko 5 November 17, 2005 Miniworkshop/Rome2, Italy
Diffuse Galactic Gamma-ray Diffuse Galactic Gamma-ray EmissionEmission
~80% of total Milky Way luminosity at HE !!!
Tracer of CR (p, e−) interactions in the ISM (π0,IC,bremss):o Study of CR species in distant locations (spectra & intensities)
CR acceleration (SNRs, pulsars etc.) and propagationo Emission from local clouds → local CR spectra
CR variations, Solar modulationo May contain signatures of exotic physics (dark matter etc.)
Cosmology, SUSY, hints for accelerator experimentso Background for point sources (positions, low latitude sources…)
Besides:o “Diffuse” emission from other normal galaxies (M31, LMC,
SMC) Cosmic rays in other galaxies !
o Foreground in studies of the extragalactic diffuse emissiono Extragalactic diffuse emission (blazars ?) may contain
signatures of exotic physics (dark matter, BH evaporation etc.)Calculation requires knowledge of CR (p,e) spectra in the entire Galaxy
Igor V. Moskalenko 6 November 17, 2005 Miniworkshop/Rome2, Italy
Transport Equations ~90 (no. of CR species)
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…)
convection convection (Galactic wind)
diffusiondiffusion
diffusive diffusive reacceleration reacceleration
(diffusion in the momentum space)
E-lossE-loss
fragmentationfragmentation radioactive decayradioactive decay
+ boundary conditions
Igor V. Moskalenko 7 November 17, 2005 Miniworkshop/Rome2, Italy
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
“Flat halo” model (Ginzburg & Ptuskin 1976)
Igor V. Moskalenko 8 November 17, 2005 Miniworkshop/Rome2, Italy
A Model of CR Propagation in the Galaxy
Gas distribution (energy losses, Gas distribution (energy losses, ππ00, brems), brems)
Interstellar radiation field (IC, eInterstellar radiation field (IC, e±± energy losses) energy losses)
Nuclear & particle production cross sectionsNuclear & particle production cross sections
Gamma-ray production: brems, IC, Gamma-ray production: brems, IC, ππ00
Energy losses: Energy losses: ionization, Coulomb, brems, IC, synchionization, Coulomb, brems, IC, synch
Solve transport equations for all CR speciesSolve transport equations for all CR species
Fix propagation parametersFix propagation parameters
“Precise” Astrophysics
Igor V. Moskalenko 9 November 17, 2005 Miniworkshop/Rome2, Italy
Wherever you look, the GeV -ray excess is there !
4a-f
EGRET data
Igor V. Moskalenko 10 November 17, 2005 Miniworkshop/Rome2, Italy
Reacceleration Model vs. Plain Reacceleration Model vs. Plain DiffusionDiffusion
Plain Diffusion
(Dxx~β-3 R0.6)
DiffusiveReacceleration
B/C ratio
Antiproton flux
Antiproton flux
B/C ratio
Igor V. Moskalenko 11 November 17, 2005 Miniworkshop/Rome2, Italy
Positron Excess ?
HEAT (Beatty et al. 2004)
GALPROP
GALPROP
1E, GeV
10
e+/e e+/e
HEAT 2000 HEAT 1994-95
HEAT combined
1E, GeV
10
Q: Are all the excesses connected?Q: Are all the excesses connected?
A: “Yes” and “No”A: “Yes” and “No”
Same progenitor (CR p or DM) for pbars, e+’s, γ’s
Systematic errors of different detectors
E > 6 GeV
Igor V. Moskalenko 12 November 17, 2005 Miniworkshop/Rome2, Italy
CR Source Distribution
SNR source
The CR source (SNRs, pulsars) distribution is too narrow to match the CR distribution in the Galaxy assuming XCO=N(H2)/WCO=const (CO is a tracer of H2)
Lorimer 2004
PulsarsCR afterpropagation
diffuse γ-raydistribution
Igor V. Moskalenko 13 November 17, 2005 Miniworkshop/Rome2, Italy
Injection intothe ISM
Life and death of e+
Energy loss
PositroniumIn flight
Direct annihilationwith bound electrons
RadiativeCapture Grains
ChargeExchange
2223
Direct annihilationwith free electrons
Positronium
Thermalisation
All sky view of 511 keV emissionKnödlseder et al 2005
Positron Annihilation Line
Positron Annihilation Line
W.Gillard
INTEGRAL-SPI
Igor V. Moskalenko 14 November 17, 2005 Miniworkshop/Rome2, Italy
Hypotheses…
Provide Provide good agreementgood agreement with all with all data (diffuse gammas, pbars, e+)data (diffuse gammas, pbars, e+) CR intensity variationsCR intensity variations Dark Matter signals Dark Matter signals
Other possibilities:Other possibilities:
Harder CR spectrum (protons, electrons) Harder CR spectrum (protons, electrons) – deviates – deviates limits from pbars, gamma-ray profileslimits from pbars, gamma-ray profiles
Influence of the Local Bubble (local component)Influence of the Local Bubble (local component) – – helps with pbars, but doesn’t help with diffuse helps with pbars, but doesn’t help with diffuse gammasgammas
Igor V. Moskalenko 15 November 17, 2005 Miniworkshop/Rome2, Italy
Diffuse emission models
0.5-1 GeV
>0.5 GeV
Dark MatterCosmic Ray
Spectral VariationsEGRET “GeV Excess”
There are two possible BUT fundamentally different explanations of the excess, in terms of exotic and traditional physics:
Dark MatterCR spectral variations
Both have their pros & cons.
from Strong et al. ApJ (2004)from de Boer et al. A&A (2005)
from Hunter et al. ApJ (1997)
Igor V. Moskalenko 16 November 17, 2005 Miniworkshop/Rome2, Italy
CR Variations in Space & Time
More frequent SN in the spiral arms
Historical variations Historical variations of CR of CR intensityintensity: : ~40kyr~40kyr ( (1010Be in Be in South Polar ice), South Polar ice), ~2.8Myr ~2.8Myr ((6060Fe in deep sea FeMn Fe in deep sea FeMn crust)crust)
Konstantinov et al. 1990
Electron/positron energy losses
Different “collecting” areas A vs. p (σ~30 mb)(different sources ?)
SN
R n
um
ber
den
sit
y
R, kpc
Igor V. Moskalenko 17 November 17, 2005 Miniworkshop/Rome2, Italy
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(d
E/d
t)-1,y
r
Electron energy loss timescale:
1 TeV: ~300 kyr 100 TeV: ~3 kyr
Igor V. Moskalenko 18 November 17, 2005 Miniworkshop/Rome2, Italy
GeV excess: Optimized/Reaccleration 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
Igor V. Moskalenko 19 November 17, 2005 Miniworkshop/Rome2, Italy
Secondary e± are seen in γ-rays !
Lots of new effects !
Improves an agreement at LE
brems
IC
Heliosphere: e+/e~0.2
electronselectrons
positronspositrons
sec.
Igor V. Moskalenko 20 November 17, 2005 Miniworkshop/Rome2, Italy
Diffuse Gammas at Different Sky RegionsDiffuse Gammas at Different Sky Regions
Intermediate latitudes:l=0°-360°,10°<|b|<20°
Outer Galaxy:l=90°-270°,|b|<10°
Intermediate latitudes:l=0°-360°,20°<|b|<60°
Inner Galaxy:l=330°-30°,|b|<5°
Hunter et al. region:l=300°-60°,|b|<10°
l=40°-100°,|b|<5°
corrected
Milagro
Igor V. Moskalenko 21 November 17, 2005 Miniworkshop/Rome2, Italy
Longitude Profiles |b|<5Longitude Profiles |b|<5°°
50-70 MeV
2-4 GeV
0.5-1 GeV
4-10 GeV
Igor V. Moskalenko 22 November 17, 2005 Miniworkshop/Rome2, Italy
Latitude Profiles: Inner Galaxy
50-70 MeV 2-4 GeV0.5-1 GeV
4-10 GeV 20-50 GeV
Igor V. Moskalenko 23 November 17, 2005 Miniworkshop/Rome2, Italy
Latitude Profiles: Outer Galaxy
50-70 MeV
2-4 GeV
0.5-1 GeV
4-10 GeV
Igor V. Moskalenko 24 November 17, 2005 Miniworkshop/Rome2, Italy
Anisotropic Inverse Compton Scattering
Electrons in the halo see anisotropic radiation Observer 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 !
Igor V. Moskalenko 25 November 17, 2005 Miniworkshop/Rome2, Italy
Extragalactic Gamma-Ray BackgroundExtragalactic 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
EGRB in differentdirections
Igor V. Moskalenko 26 November 17, 2005 Miniworkshop/Rome2, Italy
Distribution of CR Sources & Gradient in the CO/H2
CR distribution from diffuse gammas (Strong & Mattox 1996)
SNR distribution (Case &Bhattacharya 1998)
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
Pulsar distribution Lorimer 2004
Igor V. Moskalenko 27 November 17, 2005 Miniworkshop/Rome2, Italy
Again Diffuse Galactic Gamma Rays
More IC in the GC –better
agreement !
The pulsar distribution vs. R falls too fast OR
larger H2/CO gradient
Very good agreement !Very good agreement !
2-4 GeV
Igor V. Moskalenko 28 November 17, 2005 Miniworkshop/Rome2, ItalyE.Bloom’05
Igor V. Moskalenko 29 November 17, 2005 Miniworkshop/Rome2, Italy
Matter, Dark Matter, Dark Energy…
Ω ≡ ρ/ρcrit
Ωtot =1.02 +/−0.02
ΩMatter =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)
SUSY DM candidate has also other reasons to exist -particle physics…
Igor V. Moskalenko 30 November 17, 2005 Miniworkshop/Rome2, Italy
Where is the DM ?!
Flavors: Neutrinos ~ visible matter Super-heavy relics: “wimpzillas” Axions Topological objects “Q-balls” Neutralino-like, KK-like
Places: Galactic halo, Galactic center The sun and the Earth
Tools: Direct searches
– low-background experiments (DAMA, EDELWEISS)
– neutrino detectors (AMANDA/IceCUBE)
– Accelerators (LHC) Indirect searches
– CR, γ’s (PAMELA,GLAST,BESS)
from E.Bloom presentation
Igor V. Moskalenko 31 November 17, 2005 Miniworkshop/Rome2, Italy
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 !
pbars
e+
γ
GALPROP/W. de Boer et al. hep-ph/0309029GALPROP/W. de Boer et al. hep-ph/0309029
Supersymmetry: MSSM (DarkSUSY) Lightest neutralino χ0
mχ ≈ 50-500 GeV S=½ Majorana
particles χ0χ0−> p, pbar, e+, e−,
γ
Igor V. Moskalenko 32 November 17, 2005 Miniworkshop/Rome2, Italy
Longitude and Latitude Distr. E >0.5 GeV
In the plane (± 50 in lat.) Out of the plane (± 300 in long..)
Igor V. Moskalenko 33 November 17, 2005 Miniworkshop/Rome2, Italy
x y
z
2003, Ibata et al, Yanny et al.
Outer RingInner Ring
DM halo
diskbulge
Rotation Curvexy
xz
xy
xz
Expected Profile (NFW)
Halo profile
Isothermal Profile
v2M/r=cons.and
M/r3
1/r2
for const.rotation
curve
Observed Profile: EGRET data+ GALPROP
Executive Summary –de Boer et al. astro-ph/0408272
Page Number
PAMELA: Secondary to Primary ratios
plots: M.Simon
LE: sec/prim peak: one instrument -no cross calibration errors
HE: Dxx(R)
Igor V. Moskalenko 35 November 17, 2005 Miniworkshop/Rome2, Italy
PAMELA positrons
A factor of 2 will become statistically significant
Measuring absolute flux not ratio
Solar minimum conditions
After 3 years
Igor V. Moskalenko 36 November 17, 2005 Miniworkshop/Rome2, Italy
PAMELA antiprotons
After 3 years
Igor V. Moskalenko 37 November 17, 2005 Miniworkshop/Rome2, Italy
DM in Diffuse γ-rays: Spectral Signature
Ullio et al.2002
Smoking gun!
GLAST LAT
Igor V. Moskalenko 38 November 17, 2005 Miniworkshop/Rome2, Italy
Pohl et al.2003
sun
Positions of the local clouds
The Excess: Clues from the Local The Excess: Clues from the Local MediumMedium
Digel et al.2001
Observations of the local medium in different directions, e.g. local clouds, will provide a clue to the origin of the excess (assuming it exists). Inconclusive based on EGRET data
Yes No
Poor knowledge of π0-production cross
section: better understanding of π0-production
Dark Matter signal:look for spectral signatures in cosmic rays (PAMELA, BESS, AMS) and in collider experiments (LHC)
Possibility: cosmic-ray spectral variations.Further test: look at more distant clouds
Will GLAST see the excess?
EGRET data
Igor V. Moskalenko 39 November 17, 2005 Miniworkshop/Rome2, Italy
Igor V. Moskalenko 40 November 17, 2005 Miniworkshop/Rome2, Italy
σσ
Igor V. Moskalenko 41 November 17, 2005 Miniworkshop/Rome2, Italy
A.Morselli
Igor V. Moskalenko 42 November 17, 2005 Miniworkshop/Rome2, Italy
GLAST LAT simulations
EGRET intensity (>100 MeV)
LAT simulation (>100 MeV)
|b| < 20°
Seth Digel
Igor V. Moskalenko 43 November 17, 2005 Miniworkshop/Rome2, Italy
GLAST LAT: The Gamma-Ray Sky
EGRET(>100 MeV)
Simulated LAT (>100 MeV, 1 yr)Simulated LAT (>1 GeV, 1 yr)
This is an animation that steps from 1. EGRET (>100 MeV), to 2. LAT (>100 MeV), to 3. LAT (>1 GeV)
Seth Digel
Igor V. Moskalenko 44 November 17, 2005 Miniworkshop/Rome2, Italy
Conclusions I
Accurate measurements of nuclear species in CR, secondary positrons, 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 (PAMELA, Super-TIGER, AMS…)
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
Igor V. Moskalenko 45 November 17, 2005 Miniworkshop/Rome2, Italy
Conclusions II
Antiprotons: PAMELA (2006), 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
In few years we may expect major breakthroughs in Astrophysics and Particle Physics !
CERN Large Hadronic Collider – will address SUSY
Positrons: PAMELA (2006), AMS (2008): accurate and restrictive positron data
Igor V. Moskalenko 46 November 17, 2005 Miniworkshop/Rome2, Italy
Thank you !