We don ’t know it, because we don’t see it!

1. Do Gamma Rays reveal the DM of our Galaxy? We don’t know it, because we don’t see it! WdB, C. Sander, V. Zhukov, A. Gladyshev, D. Kazakov, EGRET excess of diffuse Galactic Gamma Rays as Tracer of DM, astro-ph/0508617, A&A, 444 (2005) 51

2. Do Gamma Rays reveal the DM of our Galaxy? • What is known about Dark Matter? • 23% of the Energy of the Universe • IF THERMAL RELIC THEN IT MUST BE • Weakly interacting Massive Particle (WIMP) • Annihilation with <σv>=2.10-26 cm3/s • Annihilation into Quarkpairs -> • Excess in galactic Gamma rays (π0 decays) • Indeed observed by EGRET satellite • WIMP Mass 50-100 GeV from spectrum • Halo distribution of DM by observing in • many sky directions • Data consistent with Supersymmetry From CMB + SN1a + surveys DM halo profile of galaxy cluster from weak lensing

3. Problems solvedby DM Annihilation Structure in Rotation curve “Doughnut” of stars at 14 kpc “Doughnut” of dust and H2 at 4 kpc Astronomy Astro-particle Physics Excess of Gamma rays 23%DM, Hubble-> DM Annih. x-sect. How does DM annihilate? How is DM distributed? Cosmology Particle Physics Where are signals from DM annihilation? Consistent with Supersymmetry?

4. T>>M: f+f->M+M; M+M->f+f T<M: M+M->f+f T=M/22: M decoupled, stable density (when Annihilationrate  Expansion- rate,i.e. =<v>n(xfr)  H(xfr) !) What does it imply: DM is thermal relic?Answer: low number density (like for baryons) means DM annihilated away (like baryons) Thermal equilibrium abundance Actual abundance Comoving number density WMAP -> h2=0.1130.009 -> <v>=2.10-26 cm3/s DM increases in Galaxies: 1 WIMP/coffee cup 105 <ρ>. DMA (ρ2) restarts again.. Annihilation into lighter particles, like Quarks and Leptons -> 0’s -> Gammas! T=M/22 Only assumption in this analysis: WIMP = THERMAL RELIC! x=m/T Jungmann,Kamionkowski, Griest, PR 1995

5.    f f f ~ f h,A Z    f f f   W Z 0    Z W DM Annihilation in Supersymmetry ≈37 gammas B-Fragmentation known! Hence Spectra of Positrons, Gammas and Antiprotons known! Dominant  +   A  b bbar quark pair Galaxy = Super B-Fabrik with rate 1040 x B-Factory

6. EGRET on CGRO (Compton Gamma Ray Observ.) 9 yrs of data taken in space! (1991-2000)

7. π0 π0 WIMPS IC IC Brems Brems The EGRET excess of diffuse galactic gamma rays without and with DM annihilation Fit only KNOWN shapes of BG + DMA, i.e. 1 or 2 parameter fit NO GALACTIC models needed. Propagation of gammas straightforward If normalization free, only relative point-to-point errors of ≤7% important, not absolute normalization error of 15%. Statistical errors negligible.

8. Quarks from WIMPS Quarks in protons What about background shape? No SM No SM Protons Electrons Background from nuclear interactions (mainly p+p-> π0 + X ->  + X inverse Compton scattering (e-+  -> e- + ) Bremsstrahlung (e- + N -> e- +  + N) Shape of background KNOWN if Cosmic Ray spectra of p and e- known

9. Contribution from various hadronic processes PYTHIA processes: 11 f+f' -> f+f' (QCD) 2370 12 f+fbar -> f'+fbar' 0 13 f+fbar -> g + g 0 28 f+g -> f + g 2130 68 g+g -> g + g 1510 53 g+g -> f + fbar 20 92 Single diffractive (XB) 1670 93 Single diffractive (AX) 1600 94 Double diffractive 700 95 Low-pT scattering 0 Prompt photon production: 14 f+fbar -> g+γ 0 18 f+fbar -> γ +γ 0 29 f+g -> f +γ 1 115 g+g -> g + γ 0 114 g+g -> γ + γ 0 2 GeV 4 8 16 32 64 diff.

10. Background + signal describe EGRET data!

11. Analysis of EGRET Data in 6 sky directions C: outer Galaxy A: inner Galaxy B: outer disc Total 2 for all regions :28/36  Prob.= 0.8 Excess above background > 10σ. E: intermediate lat. F: galactic poles D: low latitude A: inner Galaxy (l=±300, |b|<50) B: Galactic plane avoiding A C: Outer Galaxy D: low latitude (10-200) E: intermediate lat. (20-600) F: Galactic poles (60-900)

12. Conventional Model without DMA in 6 sky regions 2 of conventional model:663/42  Prob. = 0

13. bulge disk sun Fits for 180 instead of 6 regions 180 regions: 80in long. 45 bins 4 bins in latitude  00<|b|<50 50<|b|<100 100<|b|<200 200<|b|<900  4x45=180 bins

14. Expected Profile Observed Profile z xy xy Rotation Curve 2002,Newberg et al. Ibata et al, Crane et al. Yanny et al. x y 1/r2 halo totalDM disk xz xz bulge Inner Ring Outer Ring 1/r2 profile and rings determined from inde-pendent directions Normalize to solar velocity of 220 km/s Dark Matter distribution v2M/r=cons. and (M/r)/r2 1/r2 for const. rotation curve Divergent for r=0? NFW1/r Isotherm const. Halo profile

15. Rotation curve of Milky Way Honma & Sofue (97) Schneider &Terzian (83) Brand & Blitz(93)

16. Do other galaxies have bumps in rotation curves? Sofue & Honma

17. Apocenter Pericenter Possible origin of ring like structure Infall of dwarf galaxy in gravitational potential of larger galaxy into elliptical orbit start precessions, if matter is not distributed homogeneous. Tidal forces  gradient of field, i.e.  1/r3. This means tidal disruption only effective at pericenter for large ellipticity! Could tidal disruption of dwarf galaxy lead to ringlike structure of 1010 solar masses? N-body simulations no clear answer. All depends on initial conditions. Also no clear explanation for ring of stars of 109 solar masses.

18. Tidal disruption of satellite in potential of larger galaxy Hayashi et al., astro-ph/02003004

19. Tidal forces • 1/r3  disruption • mostly at pericenter • enhancement of DM at pericenter From Eric Hayashi

20. H2 Inner Ring coincides with ring of dust and H2 -> gravitational potential well! 4 kpc coincides with ring of neutral hydrogen molecules! Forms in presence of dust-> grav. potential well at 4-5 kpc. Enhancement of inner (outer) ring over 1/r2 profile 6 (8). Mass in rings 0.3 (3)% of total DM

21. Haloprofile without rings

22. Haloprofile with rings

23. 2  1/r2 2 toroidal Rings Determination of halo profile DM Gamma Flux: Berezinsky, Dokuchaev, Eroshenko Boost Factor  <2>/<>2  20-2000 =2 =2

24. Clustering of DM -> boosts annihilation rate Annihilation  SQUARE of DM density Clustersize: ≈ Solarsystem? Mmin 10-8 -10-6 Mסּ? Steeply falling mass spectrum. Boost factor  <2>/<>2  20-2000 From fit: B≈100 for WIMP of 60 GeV Clumps with Mmin -> dominant contribution -> MANY clumps in given direction -> same boostfaktor in all directions

25. 10 (wrong) objections against DMA interpretation • Proton spectra only measured locally. Spectra near center of • galaxy, where protons are accelerated, can be different and • produce harder gamma spectrum, as observed by EGRET. Answer: proton energy loss times larger than age of universe, so proton energy spectra will become equal by diffusion This is PROVEN by the fact that we see same spectrum and same excess in inner and outer galaxy. 2) Is background known well enough to make such strong statements? A: Background SHAPE is known, since mainly from pp collisions. Analysis does not depend on absolute fluxes from propagation models. Propagation.of gammas is straightforward.Signature is not only excess, BUT SPATIAL DISTRIBUTION OF EXCESS AS 1/r2 profile+substr. 3) Can unresolved point sources be responsible for excess? Answer: NO, if they have similar spectra as the many resolved point sources, they would reduce the data points at low energy, thus increasing the DMA contribution if shapes are fitted. Also do not expect 1/r2 profile for point sources.

26. EGRET EXCESS Positrons Antiprotons Preliminary Statistical errors only Sofue &Honma R0=8.3 kpc v Inner rotation curve R0=7.0 Outer RC Black hole at centre: R0=8.00.4 kpc R/R0 10 (wrong) objections against DMA interpretation 4) Does antiproton rate exclude interpretation of EGRET data? (L.B.) Answer:Antiproton production: p+p->pbar+X: Npbar  <ρCR ρGas> Antiproton annihilation:p+pbar-> X:  <ρGas2> <ρGas2>/ <ρGas>2 can be much larger than 1 by clustering 5) Rotation curves in outer galaxy measured with different method than inner rotation curve. Can you combine? Also it depends on R0. Answer: first points of outer RC have same negative slope as inner RC so no problem with method. Change of slope seen for every R0. 6) Ringlike structures have enhanced density of hydrogen, so you expect excess of gamma radiation there. Why you need DMA? Answer: since we fit only the shapes of signal and BG, a higher gas density is automatically taken into account and DMA is needed to fit the spectral shape of the data. 7) Is EGRET data reliable enough to make such strong statements? Answer: EGRET spectrometer was calibrated in photon beam at SLAC. Calibration carefully monitored in space. Impossible to get calibration wrong in such a way that it fakes DMA.

27. 10 (wrong) objections against DMA interpretation 7) How can you be sure that this outer ring is from the tidal disruption of satellite galaxy, so one can expect DM there? Answer: one observes rings for all three ingredients of a galaxy: gas, stars and DM. The stars cannot be part of the disk, since the thickness of the ring is a factor 20 larger than the thickness of the disk. Furthermore, very small velocity dispersion of stars 8) Is it not peculiar that the rings are in the plane of the disk? Answer: the angular momenta of halo and disk tend to align after a certain time of precession, so rings end up in plane of the disk.. 9) The inner ring was not observed as a ring of stars. How can you be sure DM concentrates there? Answer: The density of stars and dust is to high to obtain substructure in the star population. However, the ring of dust and molecular hydrogen are proof of a graviational well, which indicates DM. 10) How can one reconstruct 3D halo profiles, if one observes gamma rays only along the line of sight without knowing the distance? Answer: if one observes in ALL directions, one can easily unfold, see rings of Saturn (same problem).

28. What about Supersymmetry?

29. Allowed mSUGRA region LHC: light gauginos easily observable A0=0 tb=50 What about WMAP? Not used sofar. Large tanβ≈50->WMAP ok.

30. Gauge unification perfect with SUSY spectrum from EGRET SM SUSY Update from Amaldi, dB, Fürstenau, PLB 260 1991 With SUSY spectrum from EGRET + WMAP data and start values of couplings from final LEP data perfect gauge coupling unification! Also b->s and g-2 in agreement with SUSY spectrum from EGRET

31. Astrophysicists: What is the origin of “GeV excess” of diffuse Galactic Gamma Rays? Astronomers: Why a change of slope in the galactic rotation curve at R0 ≈ 11 kpc? Why ring of stars at 14 kpc? Why ring of molecular hydrogen at 4 kpc? Cosmologists: How is DM annihilating?A: into quark pairs How is Cold Dark Matter distributed? Particle physicists: Is DM annihilating as expected in Supersymmetry? 7 Physics Questions answered SIMULTANEOUSLY by this analysis A: DM annihilation A: DM substructure A: isothermal cored profile+substructure A: Cross sections perfectly consistent with mSUGRA for light gauginos, heavy squarks/sleptons

32. Astrophysics solution: Optimize e,p spectra to fit gammas “Optimized Model” from Strong et al. astro-ph/0406254 Protons Electrons Nucleon and electron spectra tuned to fit gamma ray data. Have to assume we live in local Bubble. Production of secondary nuclei not described.with same parameters. BUT gamma rays not well described either! B/C

33. Optimized Model from Strong et al. astro-ph/0406254 Change spectral shape of electrons AND protons C: outer Galaxy B: outer disc A: inner Galaxy π0 IC Brems E: intermediate lat. F: galactic poles D: low latitude 2 of optimized model:110/42  Prob. < 10-7

34. 300 MeV 150 MeV 100 MeV 500 MeV 1000 MeV 2000 MeV From original paper on Optimized Model Strong et al. astro-ph/0406254 longitude Real problem with conventional models: if data is perfectly fitted with sum of power spectrum+monoenergetic peak for quarks, then you cannot get good fit with whatever power spectrum you invent. In addition, DM has different spatial distribution, so fitting over all directions gives prob.<10-7 in all cases.

35. Summary 10σ EGRET excess shows all key features from DM annihilation: Excess has same shape in all sky directions: everywhere it is perfectly (only?) explainable with superposition of background AND mono-energetic quarks of 50-100 GeV Results consistent with minimal SUPERSYMMETRY Excess follows expectations from galaxy formation: cored 1/r2 profile with substructure, visible matter/DM0.02 Significance >10σ with >1400 indep. data points Excess is TRACER OF DM, since it can explain peculiar shape of rotation curve Results model independent, since only KNOWN spectral shapes of signal and background used, NO model dependent calculations of absolute fluxes. Conventional models CANNOT explain above points SIMULTANEOUSLY, especially spectrum of gamma rays in all directions, 1/r2 profile, shape of rotation curve, ring of stars at 14 kpc and ring of H2 at 4 kpc, ….

36. Future: Accelerators Are results consistent with Supersymmetry? Answer: yes, for Squarks and Sleptons in TeV range WIMP is then bino like, i.e. in this case DM would be the SUSY partner of the CMB LHC/ILC Experiments will tell!

37. EGRET? Cross sections for Direct DM detection

38. HI at 14 kpc Cosmic Enhancement Factor H2 at 4 kpc Ring of enhanced gamma radiation observed by EGRET before!

39. Fit results of Halo Parameter (<v> from WMAP) Parameter values: 180 independent sky directions i.e. ca. 1400 independent data points. only 12 free parameters. Outer ring: mainly from galactic anticenter Inner ring: mainly from galactic center Triaxial Halo: mainly from outside disc 4 kpc Boostfactor  20 for “optimized” model, 100 for “conventional” model for WIMP=65 GeV. Larger for smaller WIMP mass Dokuchaev et al: 10<B<2000, IDM2004 Sun 8 kpc 14 kpc

40. Halo density on scale of 300 kpc Sideview Topview Cored isothermal profile with scale 4 kpc Total mass: 3.1012 solar masses

41. Halo density on scale of 30 kpc Sideview Topview

42. t t t t bb bb Annihilation cross sectionsin m0-m1/2 plane (μ > 0, A0=0) tan=5 tan=50 10-24 10-27 EGRET WMAP neutralinos squarks   WW WW For WMAP x-section of <v>2.10-26 cm3/s one needs large tanβ

43. tan β dependence of relic density EGRET Point: BULK region NO Coannilation Dominant: A-exchange