Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 1
The dark connection between Canis Major, Monoceros Stream, gas flaring, the rotation curve and the EGRET excess
From EGRET excess of diffuse Galactic gamma rays• Determination of WIMP mass• Determination of WIMP halo (= standard halo + DM ring)
Confirmation of DM ring:• Rotation curve• N-body similation of Canis Major/Monoceros stream• Gas flaring
PREDICTIONS• for LHC (if SUSY)• for direct searches• for solar neutrinos
Ingredientsto this analysis
gamma spectrafor BG + DMASUSY
Particle Physics
Cosmology
Astrophysics
23%DM, thermalhistory of WIMPs annihilationcross sectionGalaxy formation
CosmicsGamma rays
Astronomers
Rotation curveDoughnut of stars at 13 kpcDoughnut of H2 at 4 kpcGas flaring
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 2
Thermal History of WIMPs
Thermal equilibrium abundance
Actual abundance
T=M/22Co
mo
vin
g n
um
ber
d
ensi
ty
x=m/TJungmann,Kamionkowski, Griest, PR 1995
WMAP -> h2=0.1130.009 -> <v>=2.10-26 cm3/s
DM increases in Galaxies:1 WIMP/coffee cup 105 <ρ>. DMA (ρ2) restarts again..
T>>M: f+f->M+M; M+M->f+fT<M: M+M->f+fT=M/22: M decoupled, stable density(when annihilation rate expansion- rate, i.e. =<v>n(xfr) H(xfr) !)
Annihilation into lighter particles, likequarks and leptons -> 0’s -> Gammas!Only assumption in this analysis:WIMP = THERMAL RELIC!
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 3
Example of DM annihilation (SUSY)
Dominant + A b bbar quark pairSum of diagrams should yield<σv>=2.10-26 cm3/s to getcorrect relic density
Quark-Fragmentation known!Hence spectra of positrons,gammas and antiprotons known!Relative amount of ,p,e+ known as well.
f
f
f
f
f
f
Z
Z
W
W 0
f~
A Z
≈37 gammas
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 4
IF DM particles are thermal relics from early universethey can annihilate with cross section as large as <v>=2.10-26 cm3/s which implies an enormous rate of gamma raysfrom π0 decays (produced in quark fragmentation) (Galaxy=1040 higher rate than any accelerator)
Expect large fraction of energetic Galactic gamma rays to come from DMA in this case.Remaining ones from pCR+pGAS-> π0+X , π0->2γ
This means: Galactic gamma rays have 2 componentswith a shape KNOWN from the 2 BEST studied reactionsin accelerators: background known from fixed target exp. DMA known from e+e- annihilation (LEP)
Conclusion sofar
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 5
Instrumental parameters:
Energy range: 0.02-30 GeVEnergy resolution: ~20%Effective area: 1500 cm2
Angular resol.: <0.50
Data taking: 1991-1994
Main results: Catalogue of point sourcesExcess in diffuse gamma rays
EGRET on CGRO (Compton Gamma Ray Observ.)
Data publicly available from NASA archive
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 6
R
Sundisc
Basic principle for indirect dark matter searches
R
Sun
bulge
disc
From rotation curve:
mv2/r=GmM/r2=cons.and(M/r)/r2
1/r2
for const. rot.curve
EXPECT MOST OF DMIN CENTRE OF GALAXY
Divergent for r=0?NFW profile1/rIsothermal profile const. 1/(r2+a2)
IF FLUX AND SHAPE MEASURED INONE DIRECTION, THEN FLUX ANDSHAPE FIXED IN ALL (=180) SKY DIRECTIONS for a given halo profile!
R1
THIS IS AN INCREDIBLE CONSTRAINT, LIKE SAYING I VERIFYTHE EXCESS AND WIMP MASS WITH 180 INDEPENDENT MEAS.
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 7
Background + signal describe EGRET data!
Blue: background uncertainty
Background + DMA signal describe EGRET data!
Blue: WI MP mass uncertainty
50 GeV
70
I CI C
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
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 8
Analysis of EGRET data in 6 sky directions
A: inner Galaxy (l=±300, |b|<50)B: Galactic plane avoiding AC: Outer Galaxy
D: low latitude (10-200)
E: intermediate lat. (20-600)F: Galactic poles (60-900)
A: inner Galaxy B: outer disc C: outer Galaxy
D: low latitude E: intermediate lat. F: galactic poles
Total 2 for all regions :28/36 Prob.= 0.8 Excess above background > 10σ.
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 9
Fits for 180 instead of 6 regions180 regions:80 in longitude 45 bins4 bins in latitude 00<|b|<50
50<|b|<100
100<|b|<200
200<|b|<900 4x45=180 bins >1400 data points. Reduced 2≈1 with 7% errorsBUT NEEDED IN ADDITION to 1/r2 profile, substructurein the form of 2 doughnut-likerings in the Galactic disc!
ONE RING COINCIDES WITHORBIT FROM CANIS MAJORDWARF GALAXY which losesmass along orbit by tidal forces
OTHER RING coincides with H2 ring
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 10
R
x y
z
2002,Newberg et al. Ibata et al, Crane et al. Yanny et al.
1/r2 profile and ringsdetermined from inde-pendent directions
xy
xz
Expected Profile
v2M/r=cons.(M/r)/r2
1/r2
for const.rotation
curveDivergent for
r=0?NFW1/r
Isotherm const.1/(r2+a2)
Dark Matter distribution
Halo profile
Observed Profile
xy
xz
Outer Ring
Inner Ring
bulge
tota
lDM
1/(r2+a2) halodisk
Rotation Curve
Normalize to solar velocity of 220 km/s
abg
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 11
N-body simulations show: Progenitor of 13 kpc ring = Canis Major Dwarf just below Galactic disc
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 12
Canis Major Dwarf orbits from N-body simulationsto fit visible ring of stars at 13 and 18 kpc
Canis Major leaves at 13 kpc tidal stream of gas(106 M☉ from 21 cm line), stars (108 M☉ ,visible), dark matter (1010 M☉, EGRET)
Movie from Nicolas Martin, Rodrigo Ibatahttp://astro.u-strasbg.fr/images_ri/canm-e.html
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 13
N-body simulation from Canis-Major dwarf galaxy
prograderetrograde
Ob
serv
ed
sta
rsR=13 kpc
Canis Major (lat=-150)
Predicted DM ring from N-bodysimulations, relying only on stars,COINCIDED PERFECTLYwith EGRET excess: • radius of ring 13 kpc• ellipticity = 0.9• angle of major axis -200
• retrograde orbit excluded
Penarrubia et al.astro-ph/0410448 astro-ph/0703601
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 14
Excess of DM from Canis Major +tidal stream indeed seen D
ark
matt
er
sig
nal (a
rb.
un
its)
CM
lat.lat.
Factor 3 more signal from region with trailing stream (from comparison of data below and above Galactic disk)
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 15
Gas flaring in the Milky Way
no ring
with ring
P M W Kalberla, L Dedes, J Kerp and U Haud, http://arxiv.org/abs/0704.3925
Gas flaring needs EGRET ring!
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 16
Enhancement of inner (outer) ring over 1/r2 profile 6 (8).Mass in rings 0.3 (3)% of total DM
Inner Ring coincides with ring of dust and H2 -> gravitational potential well!
H2
4 kpc coincides with ring ofneutral hydrogen molecules!H+H->H2 in presence of dust->grav. potential well at 4-5 kpc.
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 17
Bergstrom et al. astro-ph/0603632, Abstract:
we investigate the viability of the model using the DarkSUSY package to compute the gamma-ray and antiproton fluxes. We are able to show that their (=WdB et al) model is excluded by a wide margin from the measured flux of antiprotons.
Problem with DarkSUSY (DS):
1) Flux of antiprotons/gamma in DarkSUSY: O(1) from DMA. However, O(10-2) from LEP data Reason: DS has diffusion box with isotropic diffusion -> DMA fills up box with high density of antiprotons2) More realistic models have anisotropic diffusion. E.g. spiral galaxies have magnetic fields perpendicular to disk-> antiprotons may spiral quickly out of Galaxy. In addition: convection of particles by CR pressure.
Does antiproton data exclude interpretation of EGRET data?
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 18
Antiprotons B/C ratio
Preliminary results from GALPROP with isotropic and anisotropic propagation
Summary: with anisotropic propagation you can send charged particleswhereever you want and still be consistent with B/C and 10Be/9Be
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 19
8 Physics Questions answered SIMULTANEOUSLY if WIMP = thermal relic
• 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 13 kpc? Why ring of molecular hydrogen at 4 kpc? Why S-shape in gas flaring? • Cosmologists: How is DM annihilating?A: into
quark pairs
How is Cold Dark Matter distributed?• Particle physicists: Is DM annihilating as expected in
Supersymmetry?
A: DM substructure
A: DM annihilation
A: standard profile + substructure
A: Cross sections perfectly consistent with mSUGRA for light gauginos, heavy squarks/sleptons
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 20
Expected SUSY mass spectra in mSUGRA
mSUGRA: common masses m0 and m1/2 for spin 0 and spin ½ particles
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 21
Gauge unification perfect with SUSY spectrum from EGRET
With SUSY spectrum from EGRET + WMAP data and start values of couplings from LEP data perfect gauge coupling unification!
Up
date
fro
m A
mald
i,
dB
, F
ürs
ten
au
, P
LB
260
1991
SM SUSY
Also b->s and g-2 agree within 2σ with SUSY spectrum from EGRET
NO FREEPARAMETER
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 22
Solar neutrinos and direct DM detection
EGRET?
CDMS
SUN
EG
RET
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 23
Clustering of DM
An artist picture of what we should see if oureyes were sensitive to 3 GeV gamma rays and wewere flying with 220 km/s through the DM halo
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 24
Objections from:
Astronomers: RC shows we have no DM in GalaxyAstroparticle physicists: tune CR spectra to avoid such “exotic” explanations as DM annihilation But strong breaks in injection spectra needed and no good fit if all 180 sky directions consideredCosmologists: such high ringlike overdensities unlikelyParticle physicists: you discover new particles at accelerators, not by watching the skyConventional models CANNOT explain simultaneously:• spectrum of gamma rays in ALL directions, • 1/r2 profile of excess, • shape of rotation curve, • ghostly ring of stars at 13 kpc, • ring of H2 at 4 kpc, • gas flaring
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 25
Summary
>10σ EGRET excess shows intriguing hint that:
WIMP is thermal relic with expected annihilation into quark pairs
SPATIAL DISTRIBUTION of annihilation signal is signature for DMAwhich clearly shows that EGRET excess is tracer of DM by fact thatone can CONSTRUCT ROTATION CURVE FROM GAMMA RAYS.
DM becomes visible by gamma rays from fragmentation(30-40 gamma rays of few GeV pro annihilation from π0 decays)
Results rather model independent, since only KNOWN spectral shapes of signal and background used, NO model dependent calculations of abs.fluxes.Different models or unknown experimental problems may change boost factor and/or WIMP mass, BUT NOT the distribution in the sky.
DM interpretation strongly supported N-body simulation of Canis Major dwarf and its tidal streams coinciding with the EGRET excess
EGRET shows lots of DM mass in the tidal streams -> GAS FLARING
Wim de Boer, Karlsruhe PPC2007, Texas A&M Univ., May. 16, 2007 26
Summary on WIMP searches
Indirect detection: (SPACE EXPERIMENTS)
intriguing hint for signals from DMA for 60 GeV WIMP from gamma rays
Direct detection: (UNDERGROUND OBSERVATORIES) expected to observe signal in near future
IF we are not in VOID of clumpy DM halo
Direct production:(ACCELERATORS (LHC 2008-2018)): cannot produce WIMPs directly (too small cross section), BUT IF WIMPs are Lightest Supersymmetric Particle (LSP) THEN WIMPs observable in DECAY of SUSY particles
IF EVERY METHOD measures SAME WIMP mass, then PERFECT.In this case Dark Matter is the supersymmetric partner of the CMB!