10.07- 2009 VL Kosmologie SS/09, W. de Boer1 Gravitationslinsen Rotationskurven Indirekter Nachweis...

10.07- 2009 VL Kosmologie SS/09, W. de Boer 1

Gravitationslinsen

Rotationskurven

Indirekter Nachweis der DM ( Annihilation der DM in Materie-Antimaterie)

Direkter Nachweis der DM ( Elastische Streuung an Kernen)

Nachweismethoden der DM


Gravitationslinsen

ART: Die Ausbreitung von Licht ändert sich beim Durchgang durch ein Gravitationsfeld


Gravitationslinsen


Colliding Clusters Shed Light on Dark Matter

Observations with bullet cluster: •Chandra X-ray telescope shows distribution of hot gas•Hubble Space Telescope and others show distribution of dark matter from weak gravitational lensing•Distributions are clearly different after collision-> dark matter is weakly interacting!

Rot:sichtbaresGas

Blau: dunkle Materieaus Gravitations-potential

dunkel


http://www.sciam.com/

August 22, 2006

Simulation der “Colliding Clusters”


Center of the Coma Cluster by Hubble space telescope ©Dubinski

Discovery of DM in 1933Zwicky, Fritz (1898-1974

Zwicky notes in 1933 that outlying galaxies in Coma cluster moving much faster than mass calculated for the visible galaxies would indicate

DM attractsgalaxies withmore force->higher speed.But still bound!


Dunkle Materie im Universum

Die Rotationskurven von Spiralgalaxien sind weitgehend flach, während die leuchtende Materie eine abfallende Kurve erwarten lässt. Erklärung: dunkle Materie.

Spiralgalaxien bestehen aus einem zentralen Klumpen und einer sehr dünnen Scheibe leuchtender Materie, welche von einem nahezu sphährischen, sehr ausgedehnten Halo umgeben ist.


Messung der Masse durch Newtons Gravitationsgesetz

v=ωr

v1/r

mv2/r=GmM/r2

Milchstraße

Cygnus

Perseus

OrionSagittarius

Scutum Crux

Norma

Sun (8 kpc from center)


Do we have Dark Matter in our Galaxy?

RotationcurveSolarsystem

rotation curveMilky Way

1/r


Estimate of DM density

DM density falls off like 1/r2 for v=const.

Averaged DM density “1 WIMP/coffee cup” (for 100 GeV WIMP)


• Für Ensemble wechselwirkender Systeme im mechanischen Gleichgewicht gilt

• Für N Teilchen, also N(N-1)/2 Teilchenpaaren

Für N groß: und

02 PotKin EE

02

)1(2

2

r

mNNGvmN

NN 1 G

vrMmNx

2222 mm

Erwarte also für ´Gas` gravitativ wechselwirkender Teilchen M r ! Aber dann: vrot

2M/r = konst -> flache Rotationskurve

Virialsatz


Expansion rate of universe determines WIMP annihilation cross section

Thermal equilibrium abundance

Actual abundance

T=M/22Com

ovin

g nu

mbe

r de

nsity

x=m/TGary Steigmann/ Jungmann et al.

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(wenn Annihilationrate Expansions- 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!

10-9s


• 95% of the energy of the Universe is non-baryonic 23% in the form of Cold Dark Matter

• Dark Matter enhanced in Galaxies and Clusters of Galaxies but DM widely distributed in halo-> DM must consist of weakly interacting and massive particles -> WIMP’s

• Annihilation with <σv>=2.10-26 cm3/s, if thermal relic

From CMB + SN1a + surveys

DM halo profile of galaxycluster from weak lensing

If it is not darkIt does not matter

What is known about Dark Matter?


Kandidaten der DM

Problem: max. 4% der Gesamtenergiedes Univ. in Baryonen nach CMB und BBN.Sichtbar nur 0.5%, d.h. 3.5% in obigenKandidaten möglich. Rest der DM mussaus nicht-baryonischen Materie bestehen.

Probleme: ν < 0.7% aus WMAP Daten kombiniert mit Dichtekorrelationen der Galaxien. •Für kosmische Strings keine Vorhersagekraft. •Abweichungen von Newtons Gravitationsgesetz nicht plausibel. •WIMPS ergeben nach Virialtheorem flache Rotationskurven.In Supersymmetrie sind die WIMPSSupersymmetrische Partner der CMBd.h. Spin ½ Photonen (Photinos genannt).

†

†

?

?


Simple 3-Component Galaxy: p+e+Wimps

Interactions:

p+e <->H electromagnetic x-sectionp+p -> X strong x-section: 10-25 cm2

p+W -> p+W x-section:<10-43 cm2 (direct DM searches)W+W -> X x-section: 10-33 cm2 (Hubble expansion)

These cross sections are exactlyorder of magnitude predicted by SUSY!


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


Indirect Dark Matter Searches in theLight of ATIC, FERMI, EGRET and PAMELA

Annihilation products fromdark matter annihilation:

Gamma rays(EGRET, FERMI)

Positrons (PAMELA)

Antiprotons (PAMELA)

e+ + e- (ATIC, FERMI, HESS, PAMELA)

Neutrinos (Icecube, no results yet)

e-, p drown in cosmic rays?


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 significant fraction of energetic Galactic gamma rays to come from DMA in this case.Remaining ones from pCR+pGAS-> π0+X , π0->2γ (+some IC+brems)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


Anmerkungen zur indirekten Suche nach DM

Gamma rays: •keine Ablenkung durch das Galaktische Magnetfeld• zeigen daher in Richtung der Quelle•kaum Abschwächung in der Galaxie bei GeV Photonen• Astrophysikalische Quellen als Punktquellen erkennbar und können daher subtrahiert werden • Untergrund hat anderes (aber bekanntes) Spektrum als DMA Signal. Durch gleichzeitiges Fitten von Form des Spektrums für Signal und Untergrund können beide Beiträge direkt aus den Daten bestimmt werden, wenn man die Normierung als freier Fitparameter behandelt (data driven analysis)

Geladene Teilchen:•Ablenkung durch das Galaktische Magnetfeld, sie zeigen daher nicht in Richtung der Quelle•Wahrscheinlichkeit, dass z.B. Antiproton aus DMA im Detektor ankommt, stark abhängig vom Propagationsmodell•Keine Trennung von astrophysikalischen Punktquellen möglich


Woher erwartet man Untergrund?

Quarks fromWIMPS

Quarks in protons

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


Energy loss times of electrons and nuclei

Protons diffuse for long times without loosing energy!

-1 = 1/E dE/dt

univ

If centre would have harder spectrum, then hard to explain why excessin outer galaxy has SAME shape (can be fitted with same WIMP mass!)


Usual astrophysicist’s search strategies

Particle physicist: get rid of modeldependence by DATA DRIVEN calibration


Instrumental parameters:

Energy range: 0.02-30 GeVEnergy resolution: ~20%Effective area: 1500 cm2

Angular resol.: <0.50

Data taking: 1991-1994Main results: Catalogue of point sourcesExcess in diffuse gamma rays

EGRET on CGRO (Compton Gamma Ray Observ.)Data publicly available from NASA archive


Two results from EGRET paper

Enhancement in ringlike structure at 13-16 kpc

Called “Cosmic enhancement

Factor”Excess

101 Eγ GeV


Untergrund + DM Annihilation beschreiben Daten

Blue: background uncertainty

Background + DMA signal describe EGRET data!

Blue: WI MP mass uncertainty

50 GeV

70

ICIC

W. de Boer et al., 2005


Analyse der EGRET Daten in 6 Himmelsrichtungen

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.


EGRET Excess predicts shape of rotation curve!

Outer RingInner Ring

bulge

tota

lDM

1/r2 halodisk

Rotation Curve

Normalize to solar velocity of 220 km/s

R0=8.3 kpc

R0=7.0v

R/R0

Innerrotationcurve

Outer RC

Black hole at centre: R0=8.00.4 kpc

Sofue &Honma

Note 1: Absolute value of rotation curve depends on distances.But chance of slope can ONLYbe explained by ringlike structure.

Note 2: fact that shape of DM halocan describe shape of RC implies that EGRET excess has exactly right intensity to deliver grav. potential!


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 with mass of 2.1010M☉!

http://arxiv.org/abs/0704.3925


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.


FERMI measures GeV gamma rays + electrons

e+

e–


PublishedFERMI dataon VELA pulsar:agrees within errorswith EGRET at 3 GEVastro-ph/0812.2960

20% EGRET

Diffuse gamma rays from FERMI

100%

Why diffuse spectrum disagrees 100% with EGRET at 3 GeVwhile VELA spectrum agrees with EGRET at 3 GeV within 20%?


Indirect Dark Matter Searches using charged particles

Annihilation products fromdark matter annihilation:

Gamma rays(EGRET, FERMI)

Positrons (PAMELA)

Antiprotons (PAMELA)

e+ + e- (ATIC, FERMI, HESS, PAMELA)

Neutrinos (Icecube, no results yet)

e-, p drown in cosmic rays?


Resurs Dk1 Satellite

300 - 600 km

Bottom Scintillator

Transition Radiation Detector

(removed for tech.reasons)

Time of Flight Counters

Silicon Tracker and Permanent Magnet

Si-W Electromagnetic Calorimeter

Neutron Detector

Anticoincidence Shield

1.2 m

20.5 cm2sr

~450 kg

~10 T

The PAMELA Satellite Experiment (launched July 2006)


Positron fraction

PAMELA, positron and antiproton measurements

Positrons: excess

Galprop Pamela

Nature 458:60,2009,arXiv:0810.4995

Antiprotons: NO excess

Antiproton/proton ratio+prelim. new data, Boezio, Pamela-WS 2009

(O. Adriani et. al., PRL (2009)[0810.4994])


ATIC Balloon experiment, Nature 2008

Kaluza-Klein DM decays to lepton pairs ->peak in electron spectrum with tail from energy losses

Baltz, Hooper, hep-ph/0411053Hooper, Zurek, 0902.0593

KK x-section Y4

so mainly decay to leptons and u-quarks


Alexander Moiseev Pamela workshop May 11, 2009

FERMI electron spectrum: NO BUMP at 600 FERMI electron spectrum: NO BUMP at 600 GeVGeV

Simulating the LAT response to a spectrum with an “ATIC-like” feature:

This demonstrates that the Fermi LAT would have been able to reveal “ATIC-like” spectral feature with high

confidence if it were there. Energy resolution is not an issue with such a wide feature


HESS MAGIC

Cherenkov telescopes measure TeV gamma rays


HESS, May 2009

Electron spectrum falls off above 1 TeV


Interpretations for charged particle anomaliesMany possibilities: Background from hadronic showers with large electromagnetic component -> ap->0

astrophysical sources pulsars -> apulsar

positron acceleration in SNR -> asec

locality of sources -> aSNR

dark matter annihilation -> aDMA leptophilic? bound states? Kaluza-Klein


aDMA:DM interpretation of FERMI e-data

Models e.g. by Arkani-Hamed,Finkbeiner,Slatyer,WeinerarXiv:0810.0713 Nomura and Thaler,arXiv:0810.5397

Fit by Bergstrom et al.arXiv:0905.0333

TeV DM decaying to low scaleparticle, which can onlydecay leptonically

TeV DM forms bound state to get large boost factor via Sommerfeld enhancement


aloc :3-component e- sources: spiral arm, disc, local

3-component structureexplains e-spectrum,Pamela/Fermi anomaliesand why nothing in pbar

Shaviv et al., arXiv:0902.0376,2009sp

iral a

rm

near sources

positrons

disc

e loose energy rapidly

(dE/dt E2), hence they are

“local”

It can work!


What aboutSupersymmetry?

Assume mSUGRA5 parameters: m0, m1/2, tanb, A, sign μ


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


Expected SUSY mass spectra in mSUGRA for EGRET WIMP mass of 60 GeV

mSUGRA: common masses m0 and m1/2 for spin 0 and spin ½ particles


Annihilation cross sectionsin m0-m1/2 plane (μ > 0, A0=0)tan=5 tan=50

bb t t

WW

bb t t

WW

For WMAP x-section of <v>2.10-26 cm3/s one needs large tanβ

10-2410-27

EGRETWMAP


Mt2=(4)2Yt v2

2 Mb2=(4)2Yb v1

2

Mt/Mb = tan


tan ß = 20

EWSB: MZ2/2=(m1

2-m22 tan2ß)/ (tan2ß-1) -m2

2 for large tan ß

Pseudoscalar Higgs: MA2 = m1

2+m22 becomes very small if YtYb at large tb

(Mt2/Mb

2) = (Yt v2 sin2ß)/(Yb v2 cos2ß)=(Yt/Yb) tan2ß tan ß 53 for YtYb

tan ß = 51

m22 Yt

m12 Yb

m12 Yb

m22 Yt

EWSB requirement leads to small MA at large tan ß


Momentum dependence of annihilation cross section

v

S-wave P-wave

decoupling ns after BBM=60 GeV M=50 GeV


Expected SUSY mass spectra in mSUGRA for EGRET WIMP mass of 60 GeV

mSUGRA: common masses m0 and m1/2 for spin 0 and spin ½ particles


Gauge unification perfect with SUSY spectrum from EGRET

With SUSY spectrum from EGRET + WMAP data and start values of couplings from final LEP data perfect gauge coupling unification!

Upd

ate

from

Am

aldi

, dB

, F

ürst

enau

, PLB

260

19

91SM SUSY

Also b->s and g-2 agree within 2σ with SUSY spectrum from EGRET

NO FREEPARAMETER

WdB, C. Sander,PLB585(2004). e-Print: hep-ph/0307049


Coannihilations vs selfannihilation of DM

If it happens that other SUSY particles are around atthe 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 boostfactorsSince anni = coanni + selfanni must yield <v>=10-26 cm3/s.This means if coannihilation dominates, selfannihilation 0In present universe only selfannihilation can happen, sinceonly lightest neutralino stable, other SUSY particles decayed,so no coannihilation. If selfannihilation x-section 0, no indirectdetection.


0

0

WIMPs elastically scatter off nuclei => nuclear recoilsMeasure recoil energy spectrum in target

Direct Detection of WIMPs


Direct Detection of WIMPs


Direct Dark Matter DetectionCRESSTROSEBUDCUORICINO

DAMAZEPLIN IUKDM NaILIBRA

CRESST IIROSEBUD

CDMSEDELWEISS

XENONZEPLIN II,III,IV

HDMSGENIUSIGEXMAJORANADRIFT (TPC)

ER

Phonons

Ionization Scintillation

Large spread of technologies:varies the systematic errors, important if positive signal!All techniques have equally aggressive projections for future performanceBut different methods for improving sensitivity

L. Baudis, CAPP2003


WärmesignalWärmesignal

LadungssignalLadungssignal

ThermometerThermometer

ElektrodenElektroden zurzurLadungssammlungLadungssammlung

GeGe KristallKristallbeibei T= 0,017 KT= 0,017 K

WIMP WIMP

Ge-Kern

WärmesignalWärmesignal

LadungssignalLadungssignal

ThermometerThermometer

ElektrodenElektroden zurzurLadungssammlungLadungssammlung

GeGe KristallKristallbeibei T= 0,017 KT= 0,017 K

WIMP WIMP

Ge-Kern

Der Edelweiss Detektor

Messprinzip eines Halbleiter-Bolometers. Kommt es zu einem elastischen Stoß eines WIMP-Teilchens mit einem Atomkern des Germanium-Kristalls führt der Kern-Rückstoß zu einer Temperaturerhöhung des Kristalls, die über ein Thermometer registriert wird. Gleichzeitig ionisiert der Ge-Kern das Material in seiner Umgebung, was zu einem Ladungssignal führt, das an den Oberflächenelektroden ausgelesen wird.


Edelweiss Experiment (in Frejus-Tunnel in französichen Alpen)


Array von Phasenübergangs-

Thermometern

Schnelle (großflächige) Auslese

von Phononen

DM-Suche mit Tieftemperatur-Kalorimetern / CDMS

Sioder GeEinkristall


Rückstoß-Energie(keV)

Elektron-Rückstöße

Kern-Rückstöße

Ionisations-Energieschwelle0

0.5

1

1.5

0 50 100 150 200

Kalibration mit 252Cf Kalibration eines Ge-Bolometers durch Bestrahlung mit einer 252Cf-Neutronenquelle: Deutlich erkennbar sind zwei Ereignispopulationen, die durch das Verhältnis von Ionisations- zu Rückstoß-Energie separiert werden können. Die auf das Ionisationssignal angelegte Energieschwelle (grüne Kurve) entspricht einer Rückstoßenergie von 3.5keV. Die Bänder beschreiben die Bereiche, in denen 90% der Elektron- bzw. Kern-Rückstöße liegen.

Kalibration


Der XENON 10 Detektor


Comparison with direct searches

Note: N90%CL=n <90%CLv>

To get 90%CL one has to assumev and n : v assumed Maxwellianand NO corotation of DM halon : assume DM mass from rotation curve to be completely diffuse.

Theory: x-section can be order of magnitude lower due to matrix element uncertainties

Conclusion: can easily move upexp. limits by order of magn.and move down theory by orderof magnitude.

CDMS


Large uncertainties in direct scattering x-section

Ellis, Olive, Savage, arXiv:0801.3656


Annual Modulation as unique signature?

JuneJuneDec Dec95

97

99

101

103

105

-0.5 -0.1 0.3 0.7 1.1 1.5

±2%

0

25

50

75

100

125

-0.5 -0.1 0.3 0.7 1.1 1.5

Background

WIMP Signal

JuneJuneDec Dec

Annual modulation: v, so signal in June larger than in December due to motion of earth around sun (5-9% effect).

Junev0

galactic center

Sun 230 km/s Dec.

L. B

audi

s, C

AP

P20

03


• DAMA NaI-1 to 4: 58k kg.day• DAMA NaI-5 to 7: 50k kg.day• Full substitution of electronics and DAQ

in 2000

The data favor the presence of a modulated signal with the proper features at the 6.3 σ C.L.

0 0cos with t =152.5, T=1.00 yA t t

Running conditions stable at level < 1%

DAMA/NaI 1 to 7: Riv.N.Cim 26 n.1. (2003) 1-73

Schael, EPS2003


Warum muss DM kalt sein, d.h. nicht-relativistisch?

Antwort: Aus Galaxien-Dichteverteilung!


DM bildet Filamente erhöhter Dichte mit Galaxien und Leerräumen dazwischen

Simulation (jeder Punkt stellt eine Galaxie dar)

Steinmeitz, Potsdam


Kriterium für Gravitationskollaps:Jeans Masse und Jeans Länge

Gravitationskollaps einer Dichtefluktuation, wenn Expansionsrate 1/tExp H G langsamer als die Kontraktionsrate 1/tKon vS / λJ ist.

Oder die Jeanslänge (nach Jeans), d.h. die Länge einer Dichtefluktuation,die unter Einfluß der Gravitation wachsen kann, ist von der Größenordnung λJ = vs/ G (vS ist Schallgeschwindigkeit)(exakte hydrodynamische Rechnung gibt noch Faktor größeren Wert)

Nur in Volumen mit Radius λJ /2 Gravitationskollaps. Diesentspricht eine Jeansmasse von

MJ = 4/3 (λJ/2)3 = (5/2 vs3 ) / (6G3/2)


Die Schallgeschwindigkeit fällt a) für DM wenn die Strahlungsdichte nicht mehr dominiert und b) für Baryonen nach der Rekombination um viele Größendordnungen (von c/3 für ein relat. Plasma auf 5T/3mp für Wasserstoff) D.h. DF die vor Rekombination stabil waren, kollabieren durch Gravitation.Galaxienbildung in viel kleineren Bereichen möglich, wenn vS klein!

Abfall der Schallgeschwindigkeit nach tr

wenn Photonkoppelung wegfällt


Evolution of the universe

T / T


Jeans Masse vs. Schallgeschwindigkeit


Große Jeanslänge (relativistische Materie, Z.B. Neutrinos mit kleiner Masse)

Kleine Jeanslänge (non-relativistische Materie, Z.B. Neutralinos der Supersymmetrie)

Top-down versus Bottom-up


HDM (relativistisch vS =c/3) versus CDM


Oder für gemischte DM Szenarien …

Colombi, Dodelson, & Widrow 1995

Structure is smoothed out in model with light neutrinos

CDM WarmDM C+HDM


Millenium Simulation


• Was wissen wir über Dunkle Materie? massive Teilchen 23% der Energie des Universums schwache Wechselwirkung mit Materie Annihilation mit <σv>=2.10-26 cm3/s

• Annihilation in Quarkpaare -> Überschuss in galaktischen Gammastrahlen beobachtet?

Dunkle Materie, was wissen wir?

From CMB + SN1a

LHC Experimente werden ab 2010 klären ob dies stimmt.

10.07- 2009 VL Kosmologie SS/09, W. de Boer1 Gravitationslinsen Rotationskurven Indirekter Nachweis...

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Transcript of 10.07- 2009 VL Kosmologie SS/09, W. de Boer1 Gravitationslinsen Rotationskurven Indirekter Nachweis...