Correlations of Mass DistributionsCorrelations of Mass Distributionsbetween between

Dark Matter and Visible MatterDark Matter and Visible Matter

Yuriy Mishchenko and Chueng-Ryong JiYuriy Mishchenko and Chueng-Ryong JiNC State University NC State University

Raleigh, NCRaleigh, NC

KIAS-APCTP-DMRC Workshop on “The Dark Side of the Universe” May 24, 2005

MotivationMotivation • Universal Rotation Curves in Spiral Galaxies and

Strong Gravitational Lensing in Galaxy Clusters

provide convincing evidences of Dark Matter.• High Resolution Mass Map of CL0024+1654 is

now available from the deep imaging with the Hubble Space Telescope.

• Two dramatically different systems seem to exhibit a consistency in correlations of mass distributions between Dark Matter and Visible Matter.

Y.Mishchenko and C.Ji, PRD68, 063503 (2003)

OutlineOutline

• Gravitational Lensing

-Galaxy Clusters CL0024+1654

-Mass Map by Tyson et al.

-Simple but general theromodynamic analysis • Universal Rotation Curves

-Spiral Galaxies with different luminosities

-Consistency with the thermodynamic analysis• Discussions and Conclusions

Gravitational Lensing EffectGravitational Lensing Effect

• gravitational lensing is phenomenon of light deflection in gravitational field

• allows to restore 2D projected mass distribution

Einstein Cross Q2237+0305 Einstein Cross Q2237+0305

CL0024+1654CL0024+1654

Dark vs. Visible in Galaxy ClustersDark vs. Visible in Galaxy Clusters

from J. Tyson, G. Kochanski, I. Dell’Antonio, astro-ph/9801193

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J. Tyson, G. Kochanski, I. Dell’Antonio, astro-ph/9801193

Dark vs. Visible in Galaxy ClustersDark vs. Visible in Galaxy Clusters

• presented analysis of Hubble telescope images of strong gravitational lensing in galaxy cluster CL0024+1654

• presented detailed mass map and radial “averaged” profiles for total and visible matter

• primary conclusion was about inconsistency with Cold Dark Matter simulations (soft core)

J. Tyson, G. Kochanski, I. Dell’Antonio, 1998:J. Tyson, G. Kochanski, I. Dell’Antonio, 1998:

Correlation between Dark Matter and Visible Matter

• projected density radial profiles presented on log-log scale for the total and visible matter distribution

• if profiles were re-plotted on log-linear scale, one would observe exponential decay

anomalous flat region at about 100kpc in the visible mass profile

Flat Region around 100 kpc

Thermodynamic PrincipleThermodynamic Principle

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Dark Matter in Spiral GalaxiesDark Matter in Spiral Galaxies

Rotation Curve represents gas/stars circular orbit velocity as function of distance from the galaxy’s center

spiral galaxy NGC2403

Dark vs. Visible in Spiral GalaxiesDark vs. Visible in Spiral Galaxies

• presented analysis of a sample of spiral galaxies’ Rotation Curves classified by galaxy luminosities and normalized to vopt and ropt .

• found that majority of normalized RC in given luminosity group follow universal profiles (Universal Rotation Curves).

• described URC in terms of simple mass model: dark spherical halo + exponential thin stellar disk.

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Universal Rotation Curves in Spiral GalaxiesUniversal Rotation Curves in Spiral Galaxies

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• Dark halo contribution is parameterized,

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Luminosity Dependence of URCs Luminosity Dependence of URCs

Correlation of Mass DensityCorrelation of Mass Density

• URC can be fit in the region 0 r/ropt 2 with exponential dark hallo for all luminosities

• For larger r and are linearly correlated)log( v )log( d

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Exponential Thin Disk )/2.3exp( optv rr

It corresponds to T~105 K consistent with the temperatureof the interstellar gas.

Dark vs. Visible in Spiral GalaxiesDark vs. Visible in Spiral Galaxies

Dark vs. Visible in Spiral GalaxiesDark vs. Visible in Spiral Galaxies

M visible: 3.2 dark: a

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4.41.2 …remember obtained for CL0024+1654,

Log-Log-Linear Correlation in Spiral GalaxiesLog-Log-Linear Correlation in Spiral Galaxies

Dark vs. Visible MatterDark vs. Visible Matter

We observed Log-Log-Linear correlation with essentially the same correlation coefficient in different spiral galaxies and a galaxy cluster.

This is a remarkable coincidence…

How do we interprete?How do we interprete?

Interpretation of ResultsInterpretation of Results

• Local Thermodynamic Equilibrium since it is unlikely

that the molar mass ratio varies in a precise correlation

with the temperature ratio to make kappa constant both

for the galaxy clusters and the spiral galaxies.

• Visible matter primarily consists of H, H2 and He.

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Massive neutrinos and/or axions < 25MeVWIMP ~ 10GeV-1TeVSUSY lightest particles(e.g. neutralino)>30GeV

Discussions and ConclusionsDiscussions and Conclusions

• Correlations of mass distributions between dark matter and visible matter in two dramatically different systems, galaxy cluster and spiral galaxies, are remarkably consistent with each other.

• Based on an almost isothermal Boltzmann distribution, we find K = 2.1~4.4 which indicate the typical mass scale of dark matter particles around the order of 100 MeV.• Since this is right around the QCD mass scale, any relation between the dark matter and QCD vacuum condensates?

Things to do:Things to do:• Experimental – improve “statistics”

– large survey of dark vs. visible matter in galaxy clusters…

• Theoretical – investigate different possibilities– role of gravity in thermalization processes…

– better understanding of galaxy cluster dynamics…

– better understanding of spiral galaxy dynamics…

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C.Ji, Gungwon Kang and Jungjai Lee, work in progress…