ppt - IN2P3

Transcript ppt - IN2P3

Dark Matter:

What do we really know?

ICISE inauguration, Quy Nhon, August 11-17, 2013

Centre de Physique des Particules de Marseille (CPPM), IN2P3, Marseille, France Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing, China

Dark Matter:

What do we really know?

DM: - particle that does not emit observable radiation - interacts gravitationally… - non baryonic DM:

we know it exists in the Universe!

Assuming standard Big bang Cosmology with GR

Wealth of astrophysical evidence for

DM

 Galaxy rotation curves (V. Rubin)  Dynamics of galaxy clusters (Zwicky)  X-ray clusters  Bullet cluster (Clowe+,2006)  Gravitational lensing mass reconstruction

Evidence for dark matter: clusters

Zwicky ApJ 86 ,217 (1937): Coma Cluster velocities Clusters velocity dispersion  4 masses ~ 100 x visible mass

Galactic level: (!930’s) Oort discrepancy in the Milky Way April 18, 20015 disk: factor 2 now disappeared

Evidence for dark matter: rotation curves of spiral galaxies

V. Rubin 1970’s A.Bosma

Some numbers ...

A galaxy like the Milky Way or Andromeda has a total visible mass of about 6  10 10 M sun .

- rotation velocity is ~220 km/sec - radius about ~30 kpc Newton:

rot 

GM R



 2

rot

R G

  total mass: 3.3

 10 11 M sun

~5 times more mass than visible

 Local density 0.3- 0.4 GeV/cm3

Evidence for

dark matter:

Gravitational Lensing:

Gravitational Lensing: a property of General Relativity

Perfectly Aligned Slightly Misaligned

GR: light trajectory bent by a gravitational field.

Evidence for dark matter : Bullet Cluster

Clowe+ 2006 X-ray vs gravitational lensing : Gaz clearly separated from mass potential peaks

Dark Matter:

What do we really know?

DM: - particle that does not emit observable radiation - interacts gravitationally… - non baryonic DM common paradigm:

it exists!

Contributes to energy density in the Universe, - Measured in clusters and galaxies

The Universe energy density content after Planck

% precision Cf Y. Giraud-Heraud‘s talk

Wikipedia

Matter today ~ 31.7% energy density of the Universe

84.5% of the matter is dark matter

What do we know about DM nature ?

Particle : stable? mass? interaction cross-sections?

charge? spin ?

Constraints from non-observation in direct/indirect/LHC searches AND Observations in Astrophysics / Cosmology

Modified Gravity

Very different

candidates

dust Cold Molecular Hydrogen Black holes MACHOs SIMPs 1 Neutrino 3. Light axions 2. WIMPs Weakly interacting massive particles 10-1000GeV

Exotica

Snowmass 2013

Why WIMPs?

“WIMP”= “Weakly Interacting” Massive Particles G. Altarelli: « still most optimal candidates !»

Arguments in the 1980’s:

• • • Need for Cold Dark Matter from Large Scale Structures Very good Particle physics candidate: SUSY LSP Weak neutrino size cross sections expected which our detectors Ge, NaI were sensitive to…

Why WIMPs?

“WIMP”= “Weakly Interacting” Massive Particles Assumption: DM = Relic Particles from Big Bang If DM survives today rate annihilation < rate expansion If (rate annihilation << rate expansion), too much DM today At « freeze out » < s v > ~ 10 -26 / W h 2 cm 3 /s

Scale of weak interactions !

Coincidence with W, Z physics?

Argument in 80’s, now weaker?

Searches for massive neutrinos cross sections exclude cross-section < 0.1

s n



Particle physics preferred DM : SUSY Neutralinos ?

• A natural particle physics solution • Stable linear combination gauginos and higgsinos (LSP)    ˜   ˜   ˜ 1 0   ˜ 2 0 • SUSY > 7 parameters MSSM  no predictive power • Experimental Constraints LEP, pp, b-->s ,

LHC

...

Look everywhere possible !

Direct and Indirect Detections

WIMP searches

Direct detection Indirect detection M   M N Ge, Si, NaI, LXe, … Accelerator particle production, eg, LHC + Galactic, cluster, Universe scales… n,,

p, e +

Indirect Detection: Principle

SMMG  Sun, Earth, Galactic center, Accumulation clumps?

+ n Annihilation Possible final states: and decay t + t , lepton pairs, qq, WH, ZH, WW, ZZ ; Hadronisation Astroparticle detectors: positrons, antiprotons, antideutons gammas, neutrinos Non dedicated experiments signals,eg, AMS, are hard to exclude (cf Lee SC’s talk) Need discovery at accelerators! Still hope at LHC ?

WIMPs Indirect Detection



n,,

p, e + Light Sources Bioluminescence   track Cerenkov Light Optical M odules Compass, tilt meter Electro-optical underwater cable ~40km

Present limits Snowmass 2013 Neutrino limit: Billard+ 2013

WIMP search: direct detection

Cf. B. Sadoulet’s talk

Usual assumptions of DM Galaxy distribution in our

Usual

h y pothesis  DM = 0.3 GeV/cm 3 ,  =10 -3 , Maxwellian distribution of velocities, v rms =270 km/s Rotation curves  (

)  (

)  ( 1  

(

) /

)  ) (    ) /  a = halo core radius    ?

v Sun =220 km/s Isothermal profile  2 =0 without cusp 2 Navarro-Frenk-White 1 3 0 1 « Simplified Model »of Matter in our Galaxy : SMMG Mo Moore + 1.5

3 1.5

) Used for most comparisons… But is it the reality? Clumps? Corotation?

Galactic scale N-body simulations with Baryons

Ling+ 2009 Dark Matter Direct Detection Signals inferred from a Cosmological N-body Simulation with Baryons Fin  2 DM populations : halo DM +disk DM  only measurements can tell L CDM simulation at small scales might have problems

DM

properties from Large Scale Structures LSS

Cf beautiful movies of G. Smoot

Planck CMB map

Primordial perturbation  seeds for structure formation DM potential wells

Structure formation: Bottom-up Scenario

Density perturbations collapse into DM haloes. Small Haloes merge into bigger haloes. Gas in DM haloes collapse in galactic disks.

Shapes of galaxies change over time.

Due to merging of haloes

Hubble Tuning Fork Diagram

Before 2000: Nature of DM Hot or Cold ?

CDM is non-relativistic at decoupling, Form structures in a Hierarchical bottom-up scenario.

HDM relativistic at decoupling Mean free path large  Large structures form first

Comparisons of observations with pre-2000 N-body Simulations prefer CDM

Z=3 Z=1 Z=0 L CDM OMEGA = 0.3

LAMBDA = 0.7 H0 = 70 km/(Mpc sec) Sigma8 = 0.9 OMEGA = 1 LAMBDA = 0 H0 = 50 km/(Mpc sec) OMEGA = 0.3

LAMBDA = 0 H0 = 70 km/(Mpc sec) Sigma8 = 0.85 OMEGA = 0.3

LAMBDA = 0 H0 = 50 km/(Mpc sec) Sigma8 = 0.51 Collaboration VIRGO 1996 http://www.mpa-garching.mpg.de/~virgo/virgo/

N-Body simulations

CDM

Preferred paradigm: Most N-Body simulations use stable CDM halos as seed for structures: structures evolve, merge and cluster - DM halos cuspy density proﬁles, Triaxial halos - central density depends on the mass of the halo.

Dark matter distribution—Density profiles Cusp

Universal Density Profile from N-body simulations

NFW

Navarro, Frenk, White 1996

Cluster central density profile X-ray

~2000 : CDM crisis at small scales

Comparing data with N-body Simulations • cusp/core at GC • Missing galactic satellites

Galaxy profiles prefer core at center

CDM Simulations  cusps (Navarro, Frenk, White 1996):

Problems at smaller scales?

Observations favour Core profile rotation curves

Galaxy core vs cusp

Salucci & Frigerio Martins, 2009

Data prefer Burkert Core Profile

Too low number of visible Satellite galaxies

Satellite galaxies are seen in Milky Way, e.g. Saggittarius, MCs

Predicted number Observed number of luminous satellite galaxies 10km/s 20km/s 100km/s

Alternatives to CDM

• • • • • Self-Interacting Dark Matter (Spergel & Steinhardt 2000) Strongly Interacting Massive Particle Annihilating DM Decaying DM (eg. Zhang XM+, Nguyen Quynh Lan in // session) … • WDM: reduce the small scale power

Norma G.Sanchez, Hector J. de Vega+… Chalonge series

DM

Self-interaction constraints

DM particles might interact with themselves or other new particles, mediated by new, dark gauge bosons. Interactions affect the structures of DM halos: DM scatters  energy and angular momentum transfers For hard-sphere elastic scattering, observations of the structure of galaxy clusters 

constraints σ /m

4.5 E-7 (t/E10 yr) -2 < s /m <~ 1 cm 2 /g Bullet cluster Williams & Saha 2011 SL cluster analysis < 0.02 elliptical core MS2137-23 Miralda-Escude 2002

Non neutral DM/CHAMPs

Strong constraints :

Charged (CHAMPS) or small electric or magnetic dipole moment  coupling to the photon-baryon ﬂuid before recombination,  alter the sub-degree-scale of CMB and matter power spectrum.

Cf - Sigurdson+ , Dark-matter electric and magnetic dipole moments, (2004); - McDermott, H.-B. Yu, & K. M. Zurek, Turning off the lights: How dark is dark matter? (2011)

“Evidence” for WDM ?

• "missing satellite problem'', • ''cusp-core problem'', • mini-voids The sizes of mini-voids in the local universe: an argument in favor of a warm dark matter model? Tikhonov et al.

• HI determinations of velocity function profiles N-Body simulation Comparisons with Virgo results by Arecibo Legacy (ALFALFA)

N-Body simulations: WDM

Stable WDM looks like stable CDM on scales> 10 Mpc, - WDM create a cutoff in the matter power spectrum At late times, the evolution of the matter power spectrum is more subtle as halos form. Large WDM halos are virtually indistinguishable from stable CDM halos somewhat less concentrated, smaller halos, fluffier and less cuspy than CDM halos. The subhalo mass function drops significantly on mass scales corresponding to that cutoff scale.

Does not solve everything

Nature of DM Hot or Cold , or Warm ?

CDM is non-relativistic at decoupling, forms structures in a hierarchical, bottom-up scenario.

HDM is tightly bound by observations and LSS formation WDM 10 h/Mpc, keV WDM?

CLUES simulations, Yepes, 2010

Density profile WDM vs CDM Velocity function From Jing 2000

CDM vs WDM: HI velocity functions Virgo and Anti Virgo directions

arXiv:1005.2687: Constrained Local UniversE Simulations (CLUES) Gottloeber, Hoffman , Yepes No simple feedback mechanism to explain the factor 10 depletion from CDM?

Velocity widths in Galaxies

Velocity widths in galaxies from 21 cm HI surveys Papastergis et al, 2011; Zavala et al., 2009 NB: The red curve is for 1 keV WDM

Limits on mass of eventual WDM particles

• • • • • • Stellar dynamics in MW satellites (Boyanovsky, de Vega, Sanchez 2008; de Vega and Sanchez 2009) High-z QSO LF (e.g. Song and Lee 2009) Ly-alpha forest to constrain P(k) at small scales and different z’s (Most popular method: Narayanan et al 2000; Viel et al 2005;2008) Ly-a + SDSS results (Boyarsky et al 2009) QSO lensing ( Miranda & Maccio 2007 ) Abundance of dwarf satellites of MW (Maccio & Fontanot 2010; Polysensky & Ricotti, 2010) 

Mass WDM ~ 1- 5 keV

A fashionable (?) candidate Sterile neutrinos

Constraints on sterile neutrinos

~2000 :Problems with CDM at small scales

• • Comparing data with N-body Simulations Galactic satellites cusp/core at GC

Problems can perhaps be solved with better resolution and additional physics in N-Body simulations (SN, AGN feedback, stellar winds…)

Einasto vs NFW

CDM Simulations  cusps rather Einasto profiles than NFW Ma Chung Pei, Chang, P., Zhang, 2009

Missing satellites: CDM way out

• satellites do exist, but star formation suppressed (after reionization?) • satellites orbit do not bring them to close interaction with disk, so they will not heat up the disk.

• Local Group dwarf velocity dispersion underestimated • Galaxies may not follow dwarves Halo substructures may be probed by Lensing local Milky Way structures

More faint or dark galaxies discovered

Eg, Belokurov et al, 2010

Nature of dark matter or astrophysics process?

What we know: Comparisons of observations with N-body Simulations today prefer Non-Hot DM

Probing DM Particle properties

CL0024 Tyson, Kochanski, & Dell’Antonio (1998) Mandelbaum et al. (2006) Stacked galaxy—galaxy weak lensing signal fit with various profiles. 12/16/2009 70

Progress in Gravitational Lensing

• Strong lensing arclets • Weak lensing • Flexion

“Weak Lensing”

Distorsion of galaxy shapes by foreground matter without lensing Lensing effect

Weak Lensing mass reconstruction

Image ellipticity -> shear-> invert the equation RXJ1347.5-1145 (Bradac et al 2005)

Galaxy-scale DM density profile

Generalized NFW model → Dark Matter mass

Sensitivity of detection scales by lensing

Weak lensing: < 100 kpc Flexion: 10-100 kpc Strong lensing: 1-10 kpc

Surface density profile measurements obtained from galaxy groups in the COSMOS survey

Leauthaud et al. 2010

Dec 2012

Galaxy-galaxy lensing

Measure the correlation of shear of the background galaxies with mass of the foreground galaxies To achieve the galaxy-galaxy lensing signal, we need two important ingredients that we can extract from the data 1)redshift distribution of the lensed background galaxies 2)shape of the lensed background galaxies

Future Measurements of

DM

properties with lensing

From 100 sq deg scale at CFHT to 5000 – 20000 sq deg sky surveys

KDUST?

WFIRST?

BigBoss-like/MS-DESI can provide 3D

Euclid slide + new logo

Cosmic shear power spectra

Markovic et al. 2010 Euclid-like DE space survey +Planck: Integral effects → better than matter power spectrum

Sensitive to m_WDM < 2.5 keV

keV

WDM

effect around k=10 h/Mpc

•

Issues Galaxy evolution alters DM halos and the matter power spectrum .

Rudd, Zentner & Kravtsov, Effects of Baryons and Dissipation on the Matter Power Spectrum (2008); Pedrosa,Tissera, & Scannapieco, The joint evolution of baryons and dark matter halos, (2010); • Scannapieco +, The Aquila Comparison Project: The Effects of Feedback and Numerical Methods on Simulations of Galaxy Formation, arXiv:1112.0315.

Most of the simulations (even today) are DM-only

- DM halos extremely sensitive to the implementation of the galaxy physics in the codes. - DM halo morphologies and galaxy properties need resolutions: giant molecular cloud (GMC) sized regions .

But a lot of concern/work in the last 3 years.

N-Body simulations with baryons

Jing Y. (2005) More recent comparisons of WDM and CDM simulations.

eg Gao+, Jing+ , Yepes+ , Non-linear collapse of WDM structures

Caveat: Strong Reliance on N-body simulations might be misleading!

Baryon physics (eg.,AGN feedback) affects Matter Power Spectrum

Semboloni+ (2011) Van Daalen+(2011) Shale + :OWLS simulation  Consequences on WL cosmological parameters fits

Baryon effects different from neutrino effects

Semboloni et al. 2011

Dark Matter:

What do we really know?

DM: - particles that does not emit observable radiation - interacts gravitationally… - non baryonic DM:

we know it exists!

Or Do We Really?

Alternatives to DM?

Not so many models any more, but still… some are still doubting: eg http://www.astro.uni-bonn.de/~pavel/kroupa_SciLogs.html

Famaey & Mc Gaugh Living Reviews in Relativity, vol. 15, no. 10 2012 -

MOND-

Milgrom /TEVES-Beckenstein needs neutrinos to explain Bullet Cluster… - MOG : Moffat and collaborators Scalar-Tensor-Vector Model of gravity : “few parameters can explain away DE and DM”.

Main observational argument for alternative to DM

Local Universe: Velocity analysis  local density ~ 0.07-0.08

Dwarf galaxies: observed ones seem to be Tidal dwarf galaxies not expected to be dominant with DM models but seem to be observationnally in disk of Milky Way and Andromeda How representative is it?

Universe with Torsion

- Extension to GR: in simplest CARTAN model : (eg, Schucker and Tilquin) Lambda/DE still needed but… DM reduced (to zero?) - Difficulties with many extensions eg Gauss theorem not valid, pathologies…

• •

Summary: What do we know about

DM

Astrophysical observations

 existence of non baryonic Dark Matter

N-Body simulations and Observations of LSS

 existence of not-hot DM? . Many problems with CDM simulations can be solved with

O(1keV) WDM

Baryon physics

•

More work on baryonic N-body simulations needed!

We love CDM but need to find CDM in accelerators and DD/ID experiments!

A mysterious

Dark

Universe !

What we know is only 4-5 % of the energy density of the Universe We now measure with

precision

the extent of our ignorance ! Graph source: Wikipedia

cảm ơn bạn

Thank you

谢谢

Towards a large South Pole Dome A Kunlun Dark Universe Survey Telescope (KDUST)

 Multiprobe measurements (SNIa, Weak Lensing, BAO, Clusters) for cosmology and ancillary science  First stage 2011-2015: 3 x 67 cms telescopes (AST3) - one AST3 installed in Dome A in fall 2011,  THCA contributes to one AST3 and take responsibility for SN search (need computing capability) - Collaboration with Australia, US and France  2.5 m KPATH (Kunlun Pathfinder): 2013(?)-2017  Larger (> 4m) KDUST: Timescale too early to define!

Antarctica Schmidt Telescopes (AST3)

Aperture ： 67 cm ； FOV ： 4.2

°； Wave Band ： 400nm-900nm (

i ,

g, r

or IR? filter for 3 telescopes ); Scale ： 1 arcsec/pixel; Image quality ： 80 ％ energy encircled in one pixel ； CCD: 9micron /pixel, 10580x10560 (95.22mm x 95.05mm image area) ； Type: STA1600 ；  Working mode: frame transfer readout  Focal length: 1867mm  Distorsion in the whole field: 0.012% (less than 1 pixel)  Total optical length: 2.2m

First AST3 in Dome A, some data in 2012

Summer 2011 in Xuyu Dec 2011 in Dome A

The Kunlun Dark Universe Survey Telescope

5000 sq deg down to mag 29