Gravitationslinsen Rotationskurven Direkter Nachweis der ... · Gravitationslinsen Rotationskurven Direkter Nachweis der DM Nachweismethoden der DM Wim de Boer, Karlsruhe Kosmologie

Gravitationslinsen

Rotationskurven

Direkter Nachweis der DM

Nachweismethoden der DM

Wim de Boer, Karlsruhe Kosmologie VL, 23.01.2012 1

Direkter Nachweis der DM( Elastische Streuung an Kernen)

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

• 95% of the energy of the Universe is non-baryonic23% in the form of Cold Dark Matter

• Dark Matter enhanced in Galaxies and Clusters of Galaxies but DM widely distributed in halo >

From CMB + SN1a + surveys

If it is not darkIt does not matter

What is known about Dark Matter?


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

DM halo profile of galaxycluster from weak lensing

It does not matter

Thermische Geschichte der WIMPS

Thermal equilibrium abundance

Actual abundance

er d

ensi

ty G

riest

, PR

199

5

WMAP -> h2=0.1130.009 -><v>=2.10-26 cm3/s

T>>M: f+f->M+M; M+M->f+fT<M: M+M->f+fT=M/22: M decoupled, stable density(wenn Annihilationsrate Expansions-rate, i.e. =<v>n(xfr) H(xfr) !)


T=M/22Com

ovin

g nu

mb

x=m/T

Jung

man

n,K

amio

nkow

ski,

DM nimmt wieder zu in Galaxien:1 WIMP/Kaffeetasse 105 <ρ>.DMA (ρ2) fängt wieder an.

Annihilation in leichtere Teilchen, wieQuarks und Leptonen -> 0’s -> Gammas!

Einzige Annahme: WIMP = thermischesRelikt, d.h. im thermischen Bad des frühen Universums erzeugt.

How do particles annihilate?

~~e+

e-

q

q

LEP collider:e+e- annihilation ~~

~~

e

ee

photon annihilation

In CM: Eq=Eemonoenergetic quarks


monoenergetic quarksfrom monoenergetic leptons

Quarks fragment into jets,mostly light mesons:π+,π-,π0

π0 decays 100% in 2 photonsSo as many photons as charged particlesfrom annihilationOn average: 37 photons pro annihilation into quarks at LEPSpectral shape VERY WELL MEASURED

DM Annihilation in Supersymmetrie

f

f

f

f

f

f

ZW0

f~ A Z

≈37 gammas


Dominant + A b bbar quark pair

B-Fragmentation bekannt!Daher Spektren der Positronen,Gammas und Antiprotonen bekannt!

ZW 0

Galaxie = Super B-Fabrik mit Rate 1040 x B-Fabrik

Indirect Dark Matter Searches 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?

Pamela, arXiv:1001.3522v1

PAMELA Positron excess


Origin?

Depends on whom you ask!

My assumption:

|Data>= ap->0 |Background> + aDMA |DMA>+ asec |SNR> + alocal |SNR(x)> + apulsar |Pulsar>


sec local pulsar

Unitarity must be fulfilled. However, each component has enough uncertainty

to saturate observations

For details: WdB, AIP Conf.Proc.1200:165-175,2010. arXiv:0910.2601 [astro-ph.CO]

AMS: large magn. spectrometer with redundant particle ID


AMS installed on ISS in May,2011


Testflight 1998

AMS-02 from CERN to Cape Canaveral on 26.08.2010

Loading the 7.5 tons at Geneva airport


GALPROP Antiprotons Donata et al. [0810.5292]

Antiprotons: saturated by background?

Pamela

B,ar

Xiv:0

910.

2027


GALPROP (with and without) convection has deficit ofantiprotons. Darksusy and others (which only look into charged particles, no gamma rays) can saturate data.

Geba

uer

and

WdB

Propagation of charged cosmic rays (CR)

This does not allow for significant convection, since CR‘s do not return to disc->too little secondary productionfrom CR hitting gas in disc

HOWEVER, significant convection observed by ROSAT

CRs propagation can be


Present models use isotropic propagation, i.e. same diffusion constant in halo and disc.

p p gdescribed by diffusion and convection, very much like a drop of ink inside streaming water (with water velocity=convection velocity)

Radiaactive clocks like 10Be determine time from source to Sun (107 yrs) Need slow diffusion in disc, but particlesin halo drift to outer spacewith convectionWith convection little flux of charged particles from DMA, since particles drift away.

Present models: isotropic propagation

Isotropic propagation leads to “propagation enhancement”:of charged particles: trapping of chargedparticles in “leaky” Galaxy for a long time->

Flux of gamma rays from DMA Flux of antiprotons in such propagation models,


Is this right?

Flux of antiprotons in such propagation models,

Although we KNOW from LEP that fragmentationgives many more photons than antiprotons

Not nessarily!

CONVECTION = negligible with isotropic propagation in contrast to observation

Diffuse gamma rays

Great advantage of pointing to the source and propagation is „straightforward“ without dependence on magnetic field and diffusion,hi h l h d i l


which plagues charged particles.

Astrophysical point sources can be pinpointed and subtracted.

Sundisc

Basic principle for indirect dark matter searches

R

Sun

bulge disc

From rotation curve:

Forces: mv2/r=GmM/r2

or M/r=const.for v=cons.and(M/r)/r2

1/r2

for flat rotation curve

R1


Expect highest DM densityIN CENTRE OF GALAXY

IF FLUX AND SHAPE MEASURED INONE DIRECTION, THEN FLUX ANDSHAPE FIXED IN ALL (=120) SKY DIRECTIONS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

THIS IS AN INCREDIBLE CONSTRAINT, LIKE SAYING I VERIFYTHE EXCESS AND WIMP MASS WITH 180 INDEPENDENT MEAS.

Wie sehen Haloprofile aus?

1) Erwarte für Galaxie mit flacher Rotationskurve: 1/r2

2) Was passiert für r 0?N-body Simulationen : 1/r „cuspy profile“)Übergang von 1/r2 nach 1/r beschrieben durchNFW P fil


NFW Profil:

(zuerst von Navarro, Frenk, White veröffentlicht)Aber viele Rotationskurven zeigen eher konst, wenn r 0 (isothermisches Profil)

3) Clumps zeigen Einasto-Profil ( 1/rn n<1)

Boostfactor by DM clumping


An artist picture of what we should see if our eyes were sensitive to 3 GeV gamma rays: clumps of DMin diffuse DM halo (from hierarchical growth of galaxy combined with tidal disruption of clumps

diffDM

clumpclump

How to calculate DMA flux?

Beitrögevon Sub-struktur(Ringe?)


esis, 20

10. KI

TRotation curve Milky Way

VLBI pointWeber, dB, arXiv:0910.4272


Web

er, Th

e

Oort limit on local densityprevents larger DM contr. (Hipparcos data

VERA: VLBI Exploration of Radio Astrometry

VLBI = Very LargeBaseline Interferometryallows very precise parallaxmeasurements.Maser light fromMolecular Clouds allowslarge distance interferometry

Japan


A. Honma et al, PASJ 2007, Astrometry of Galactic Star-Forming Region Sharpless 269 with VERA:Parallax Measurements and Constraint on Outer Rotation Curve at 13 kpc

large distance interferometry

Measured parallax of 1896asat distance of >5 kpc over 1 yr-> rotation velocity

Weitere VLBI Daten


W.dB, M. Weber,arXiv:1011.6323

Substrudture in HALO PROFILE ?

= NFW (diffuse)+Einasto (clumps)(expected from N-body simulations)

inner


Motivation for “outer ring”: Monocerus ring of stars (SDSS, 2002), discussed as tidal disruption of Canis Major dwarf AND gas flaring

Motivation for “inner ring”: dust ring

innerring outer

ring

Inner Ring coincides with ring of dust and H2 ->gravitational potential well!

H2


Dust ring at 4 kpc 4 kpc coincides with ring ofneutral hydrogen molecules!H+H->H2 in presence of dust->grav. potential well at 4-5 kpc.

The Milky Way and its satellite galaxies


Canis Major

Tidal force ΔFG 1/r3

Tidal streams of dark matter from CM and Sgt

CMSun


CM

Sgt

From David Law, Caltech

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

Core of Canis Major Dwarf just below Galactic disc


Tidal disruption of Sagittarius


Movie from Kathryn Johnston (Wesleyan University )http://astsun.astro.virginia.edu/~mfs4n/sgr/

N-body simulation from Canis-Major dwarf galaxy

serv

ed s

tars

R=13 kpc


prograde retrograde

Obs Canis Major (b=-150)

Gas flaring in the Milky Way

no ring

P M W Kalberla, L Dedes, J Kerp and U Haud, arXiv:0704.3925


no ring

with outer ring

Gas flaring needs also outer ring with mass of 2.1010M☉!

Mass in ring few % of total

Woher erwartet man Untergrund?

Quarks fromWIMPS


Quarks in protons

Background from nuclear interactions (mainly p+p-> π0 + X -> + Xinverse Compton scattering (e-+ -> e- + )Bremsstrahlung (e- + N -> e- + + N)

Shape of background KNOWN if Cosmic Ray spectra of p and e- known

Data driven analysis of gamma ray data(publicly available from NASA archive)

Idea: Fit known shapes of 3 main components:

Inverse Compton:(IC) CR electron density x ISRFBremstrahlung:(BR) CR electron density x gas densityPCRPGas scattering:(0) CR proton density x gas density


Main unknowns: CR electron densityCR proton density

(both measured locally, i.e. at a single point in Galaxy)

Alternative to data driven analysis: compare data with Galactic Propagation ModelBest publicly available model: GALPROP (Moskalenko,Strong…)

Background mainly in disk


Usual astrophysicist’s search strategies


Particle physicist: get rid of modeldependence by DATA DRIVEN calibration

I t t l t

EGRET (Energetic Gamma Ray Experiment Telescope.)Data publicly available from NASA archive

EGRET excessHunter et al. 1997


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

Experimentelle Schwierigkeiten

Experiment hat kein MagnetfeldDadurch werden zwei Spuren (e+e.) von konvertiertes Gamma ab ca. 5 GeV kaum getrennt.Gamma unterscheidet sich von Elektron nur nochdurch doppelt so hohe Ionisationsverluste.

Lokale Punktquellen, wie Pulsare, müssen abgezogen werden.


q g gKein großes Problem, wenn man über genügend großeRaumbereiche integriert (diff. Beitrag prop. Raumwinkel)

Bei hohen Energien erzeugt elektromagnetischer Schauer„backsplash“ von Teilchen, die Vetozähler setzen und dadurch Ereignis verwerfen.Resultat: Experimente widersprechen sich, z.B. EGRET vs FERMIOder FERMI Reprocessing P6 vs. P7,

Untergrund + DM Annihilation beschreiben Daten

Background + DMA signal describe EGRET data!

50 GeV

70MPS


Blue: background uncertainty Blue: WIMP mass uncertainty

70Brems .

ICWIM

0

IC

0 WIM

PS

Brems .

IC

W. de Boer et al., 2005

FERMI measures GeV gamma rays + electrons


e+

e–

FERMI diffuse spectra from Galactic centre

without DMA with DMA

0+IC+BR


DMA60 GeV

neutralino


Es gibt interessante Hinweise für Teilchencharakterder DM:

a) Überschuss an Gammastrahlung von EGRET gemessen(aber FERMI misst weniger und Konsistenz mit Antiprotonenfluss steht nach aus, abhängig vomPropagationsmodell)

Zusammenfassung


Propagationsmodell)

b) Jährliche Modulation der Signale in Libra/DAMA(aber inkonsistent mit anderen Experimenten)

c) Überschüsse in Positronen (PAMELA Satellit)(aber Pulsare oder andere Quellen bieten gute Lösung)

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Gravitationslinsen Rotationskurven Direkter Nachweis der ... · Gravitationslinsen Rotationskurven Direkter Nachweis der DM Nachweismethoden der DM Wim de Boer, Karlsruhe Kosmologie