EGRET excess of diffuse Galactic Gamma Rays interpreted as Dark Matter Annihilation

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Boer, Christian Sander, Valery Zhukov Univ.

Alex Gladyshev structure formation Dubna

diffuse Gamma Rays show excess in all sky

monoenergetic quarks WIMP mass between 50 and

distribution from sky map Data consistent with

1 EGRET excess of diffuse Galactic Gamma Rays interpreted as Dark Matter Annihilation Wim de Boer, Christian Sander, Valery Zhukov Univ. Karlsruhe From CMB + SN1a + Dmitri Kazakov, Alex Gladyshev structure formation Dubna Outline (see astro-ph/ ) EGRET Data on diffuse Gamma Rays show excess in all sky directions with the SAME energy spectrum from monoenergetic quarks WIMP mass between 50 and 100 GeV from spectrum of EGRET excess Halo distribution from sky map Data consistent with Supersymmetry March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 1

2 DM annihilation in Supersymmetry χ χ ~ f f f χ χ A f f χ χ Z f f χ χ χ W χ ± χ 0 W χ Z Z 37 gammas Dominant diagram for WMAP cross section in MSSM: χ + χ A b bbar quark pair B-fragmentation well studied at LEP! Yield and spectra of positrons, gammas and antiprotons well known! Galaxy = SUPER-B-factory with luminosity some 40 orders of magnitude above man-made B-factories March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 2

3 Jungmann,Kamionkowski, Griest, PR 1995 Basics from cosmology: Hubble const. determines WIMP annihilation x-section Thermal equilibrium abundance Comoving number density Actual abundance T=M/22 T>>M: f+f->m+m; M+M->f+f T<M: M+M->f+f T=M/22: M decoupled, stable density (wenn annihilation rate expansion rate, i.e. Γ=<σv>nχ(x fr ) H(x fr )!) More precisely by solving Boltzmann eq. H-Term takes care of decrease in density by expansion. Right-hand side: annihilation and production. Ωh 2 = mχnχ/ρ c [cm 3 /s]/<σv> (<σv> independ. of mχ!) Present WMAP Ωh 2 =0.113±0.009 requires <σv> cm 3 /s x=m/t DM density increases locally after galaxy formation. In this room: 1 WIMP/coffee cup 10 5 averaged density. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 3

4 Basics of background and signal shapes RED=flux from DM Annihilation Yellow = backgr. Blue = BG uncert. WIMP MASS GeV π 0 WIMPS IC π 0 WIMPS IC Extragal. Bremsstr. Extragal. Bremsstr. Blue: uncertainty from background shape Blue: uncertainty from WIMP mass March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 4

5 Basics of background and signal shapes No SM No SM Protons Quarks from WIMPS Electrons Quarks in protons March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 5

6 Energy loss times of electrons and nuclei τ -1 = 1/E de/dt τ univ Protons diffuse for long times without loosing energy! If centre would have harder spectrum, then hard to explain why excess in outer galaxy has SAME shape (can be fitted with same WIMP mass!) March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 6

7 EGRET on CGRO (Compton Gamma Ray Observ.) 9 yrs of data taken ( ) Main purpose: sky map of point sources above diffuse BG. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 7

8 Basics of astro-particle physics Gamma Ray Flux from WIMP annihilation in given direction ψ: Similar expressions for: pp->π 0 +x->γγ+x, (ρ given by gas density, highest in disc) eγ->eγ, en->eγn, (ρ given by electron/gamma density, highest in disc) Extragalactic Background (isotropic) DM annihilation (ρ 1/r 2 for flat rotation curve) All have very different, but known energy spectra. Cross sections known. Densities not well known, so keep absolute normalization free for each process. Fit shape of various contributions with free normalization, but normalization limited by experimental overall normalization error, which is 15% for EGRET data. Point-to-point errors 7% (yields good χ 2 ). March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 8

Executive Summary for fits in 360 sky directions xy xz Expected

and ρ M/r 3 ρ 1/r 2 for const. rotation curve Divergent for r=0?

z Rotation Curve x disk 2003, Ibata et al, Yanny et al.

9 Executive Summary for fits in 360 sky directions xy xz Expected Profile Observed Profile v 2 M/r=cons. and ρ M/r 3 ρ 1/r 2 for const. rotation curve Divergent for r=0? NFW 1/r Isotherm const. z Rotation Curve x disk 2003, Ibata et al, Yanny et al. bulge y totaldm 1/r 2 halo Inner Ring Outer Ring Halo profile March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 9

Strong, Moskalenko, Reimer, APJ.613, astro-ph/0406254 Excess of Diffuse Gamma Rays above 1 GeV (first publications by Hunter et al, Sreekumar et al. (1997) A B C π 0 Inv.

10 Strong, Moskalenko, Reimer, APJ.613, astro-ph/ Excess of Diffuse Gamma Rays above 1 GeV (first publications by Hunter et al, Sreekumar et al. (1997) A B C π 0 Inv. Compton Bremsstrahlung 2004 D E F A: inner Galaxy (l=±30 0, b <5 0 ) B: Galactic plane avoiding A C: Outer Galaxy D: low latitude ( ) E: intermediate lat. ( ) F: Galactic poles ( ) March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 10

11 Excess of Diffuse Gamma Rays has same spectrum in all directions compatible with WIMP mass of GeV Egret Excess above extrapolated background from data below 0.5 GeV Statistical errors only Excess same shape in all regions implying same source everywhere Important: if experiment measures gamma rays down to 0.1 GeV, then normalizations of DM annihilation and background can both be left free, so one is not sensitive to absolute background estimates, BUT ONLY TO THE SHAPE, which is much better known. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 11

Diffuse Gamma Rays for different sky regions Good Fits for WIMP masses between 50 and 100 GeV A: inner Galaxy B: outer disc C: outer Galaxy D: low latitude E: intermediate lat.

12 Diffuse Gamma Rays for different sky regions Good Fits for WIMP masses between 50 and 100 GeV A: inner Galaxy B: outer disc C: outer Galaxy D: low latitude E: intermediate lat. F: galactic poles 3 components: galactic background + extragalactic bg + DM annihilation fitted simultaneously with same WIMP mass and DM normalization in all directions. Boost factor around 70 in all directions and statistical significance > 10σ! March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 12

13 Optimized Model from Strong et al. astro-ph/ Change spectral shape of electrons AND protons March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 13

14 Optimized Model from Strong et al. astro-ph/ Change spectral shape of electrons AND protons Electrons Protons B/C Nucleon and electron spectra tuned to fit gamma ray data. Apart from the difficulty to have inhomogeneous nuclei spectra (SMALL energy losses!) the model does NOT describe the spectrum IN ALL DIRECTIONS! March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 14

15 Optimized Model from Strong et al. astro-ph/ Change spectral shape of electrons AND protons 100 MeV 150 MeV 300 MeV 500 MeV 1000 MeV 2000 MeV March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 15

Optimized Model from Strong et al. astro-ph/0406254 Change spectral shape of electrons AND protons Probability of optimized model if χ2 measured in 360 sky directions and integrate data with E>0.

16 Optimized Model from Strong et al. astro-ph/ Change spectral shape of electrons AND protons Probability of optimized model if χ2 measured in 360 sky directions and integrate data with E>0.5 GeV: χ2= 962.3/324 for Optimized Model without DM +correl. errors: Prob = < χ2= 306.5/323 for Optimized Model +DM +correl. errors: Prob = Boostfactor=25 for OM vs 70 for CM March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 16

17 Determining halo profile DM Gamma Ray Flux: =2 1/r 2 2 Gaussian ovals March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 17

18 Fit results of halo parameters Parameter values: (<σv> from WMAP) Enhancement of rings over 1/r 2 profile 2 and 7, respectively. Mass in rings 1.6 and 0.3% of total DM H 2 H Boostfactor Dokuchaev et al: 10<B<200, IDM2004 R [kpc] 14 kpc coincides with ring of stars at kpc due to infall of dwarf galaxy (Yanny, Ibata,..) 4 kpc coincides with ring of neutral hydrogen molecules! 4 March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 18

19 Halo density on scale of 300 kpc Sideview Topview Cored isothermal profile with scale 4 kpc Total mass: solar masses March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 19

20 Halo density on scale of 30 kpc Sideview Topview March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 20

<b<90 0 Halo parameters from fit to 180 sky directions: 4 long.

21 Longitude fits for 1/r 2 profile with/w.o. rings WITHOUT rings E > 0.5 GeV WITH 2 rings DISC 10 0 <b<20 0 DISC 10 0 <b< <b< <b< <b< <b<90 0 Halo parameters from fit to 180 sky directions: 4 long. profiles for latitudes <5 0, 5 0 <b<10 0, 10 0 <b<20 0, 20 0 <b<90 0 (=4x45=180 directions) March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 21

22 Longitude on linear scale BELOW 0.5 GeV ABOVE 0.5 GeV March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 22

23 Do other galaxies have bumps in rotation curves? Sofue & Honma March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 23

24 Normalization of background: Compare with GALPROP, which gives absolute prediction of background from gas distributions etc. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 24

25 Background scaling factors Background scaling factor = Data between 0.1 and 0.5 GeV/GALPROP GALPROP = computer code simulating our galaxy (Moskalenko, Strong) March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 25

26 Normalization of DMA -> Boost factor (= enhancement of DMA by clustering of DM) March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 26

$Clustering of DM -> boosts annih. rate Annihilation DM density squared! Clustersize: 10 14 cm =10x solar system M min סּM 10-8 -10-6 Cluster density 25 pc -3 Halo mass fraction in clumps: 0.$

27 Clustering of DM -> boosts annih. rate Annihilation DM density squared! Clustersize: cm =10x solar system M min סּM Cluster density 25 pc -3 Halo mass fraction in clumps: From Berezinsky, Dokuchaev, Eroshenko Boost factor <ρ 2 >/<ρ> Clumps with M min give the dominant contribution to DM annihilation -> many in a given direction -> similar boost factor in all directions March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 27

28 What about Supersymmetry? Assume msugra 5 parameters: m 0, m 1/2, tanb, A, sign µ March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 28

29 10-27 Annihilation cross sections in m 0 -m 1/2 plane (µ > 0, A 0 =0) tan=5 tan=50 bb t t bb t t EGRET WMAP ττ WW ττ WW For WMAP x-section of <σv> cm 3 /s one needs large tanβ March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 29

30 Coannihilations vs selfannihilation of DM If it happens that other SUSY particles are around at the freeze-out time, they may coannihilate with DM. E.g. Stau + Neutralino -> tau Chargino + Neutralino -> W However, this requires extreme fine tuning of masses, since number density drops exponentially with mass. But more serious: coannihilaition will cause excessive boostfactors Since σ anni = σ coanni + σ selfanni must yield <σv>=10 26 cm 3 /s. This means if coannihilation dominates, selfannihilation 0 In present universe only selfannihilation can happen, since only lightest neutralino stable, other SUSY particles decayed, so no coannihilation. If selfannihilation x-section 0, no indirect detection. CONCLUSION: EGRET data excludes largely coannih. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 30

EGRET excess interpreted as DM consistent with WMAP, Supergravity and electroweak constraints Stau LSP Stau coannihilation m A resonance MSUGRA can fulfill all constraints from WMAP, LEP, b->sγ, g-2

31 EGRET excess interpreted as DM consistent with WMAP, Supergravity and electroweak constraints Stau LSP Stau coannihilation m A resonance MSUGRA can fulfill all constraints from WMAP, LEP, b->sγ, g-2 and EGRET simultaneously, if DM is neutralino with mass in range GeV and squarks and sleptons are O(1 TeV) Incomp. with EGRET data WMAP No EWSB Bulk EGRET March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 31

32 SUSY Mass spectra in msugra compatible with WMAP AND EGRET LSP largely Bino DM is supersymmetric partner of CMB Charginos, neutralinos and gluinos light March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 32

33 Unification of gauge couplings SM SUSY Update from Amaldi, db, Fürstenau, PLB With SUSY spectrum from EGRET data and start values of couplings from final LEP data perfect gauge coupling unification possible March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 33

34 Comparison with direct DM Searches Spin-independent Spin-dependent DAMA ZEPLIN CDMS Edelweiss Projections Predictions from EGRET data assuming Supersymmetry March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 34

$Positron fraction and antiprotons from present balloon exp.$ for GAMMA RAYS but fluxes dependent on propagation!

35 Positron fraction and antiprotons from present balloon exp. Positrons Antiprotons Signal Background Signal Background SAME Halo and WIMP parameters as for GAMMA RAYS but fluxes dependent on propagation! DMA can be used to tune models: at present no convection, nor anisotropic diffusion in spiral arms. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 35

36 Summary 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 GeV Results and x-sect. in agreement with SUPERSYMMETRY Excess follows expectations from galaxy formation: 1/r 2 profile with substructure, visible matter/dm 0.02 Excess connected to MASS, since it can explain peculiar shape of rotation curve These combined features provide FIRST (>10σ) EVIDENCE that DM is not so dark and follow ALL DMA expectations imagined so far. Conventional models CANNOT explain above points SIMULTANEOUSLY, especially spectrum of gamma rays in all directions, DM density profile, shape of rotation curve, stability of ring of stars at 14 kpc,.. March. 7, 2005 Moriond Electroweak, 2005, W. de Boer, Univ. Karlsruhe 36

Excess of EGRET Galactic Gamma Ray Data interpreted as Dark Matter Annihilation

Excess of EGRET Galactic Gamma Ray Data interpreted as Dark Matter Annihilation Wim de Boer, Marc Herold, Christian Sander, Valery Zhukov Univ. Karlsruhe Alex Gladyshev, Dmitri Kazakov Dubna Outline (see