Transcript What constitutes the dark matter?

What constitutes the dark matter?
Dr. Theo M. Nieuwenhuizen
Institute for Theoretical Physics
University of Amsterdam
Sterrenwacht Vesta
Oostzaan, 17-10-2009
Outline
What is dark matter?
Where is it located?
Two forms of dark matter: Macho’s and/or Wimp’s
Searches
Solutions
Discovery of dark matter
• 1931 Jan Oort Leiden: motions in our galaxy are “too fast”
• perpendicular to galactic plane: stars should escape
• In the plane: stars should escape from their elliptic orbit
• Explanation: there is more matter than we see: dark matter
1900 - 1992
• 1932 Fritz Zwicky: clusters of galaxies
• They rotate too fast around each other
• Explantion: dark matter
1898 - 1974
Rotation of galaxies
Rotation speed nearly independent of location
Andromeda Nebula in Ultraviolet (HST 2009)
Planet
Distance to sun
Rotation speed
Mercurius
0.45 AE
48 km/s
Aarde
1 AE = 92 million mi
30 km/s
Jupiter
5 AE
13 km/s
p
• In solar system outer planets are slower
• In galaxies there must be matter out of the
center
• Where is the dark matter?
Explanantions
• Planets? MACHOs:
Massive Astrophysical Compact Halo Objects
• Heavy particles (“cold dark matter”) ?
WIMPs: Weakly Interacting Massive Particles
• Newton’s law is not valid?
• Hydrodynamics, fluid mechanics
Hydrodynamics
• 400.000 yr after big bang: plasma becomes gas (hydrogen,
He)
• Jeans 1904: formation of proto-clusters
fall  time 1/ density, diameter  sound  speed  fall  time, mass 100.000 suns
• Gibson 1996: Viscosity leads to fragmentation in gas balls
of a few earth masses
• If gas balls coagulate, stars form
• Then Jeans cluster becomes visible as globular cluster
• Most gas balls cool and freeze, their clusters are invisible

Sir James
Hopwood
Jeans
1877-1946
Carl H.
Gibson
* 1935
100.000.000 Jeans clusters around Galaxy,
149 visible as globular star clusters.
Those clusters form the galactic dark matter.
2
Isothermal 1/ r density distribution explains the large
rotation speeds far from the center
More than 2000 objects with earth
mass observed in microlensing
Rudy E.
Schild
*1942
Omega Centauri: Globular star cluster in Milky Way
Young blue
stars,
older yellow
stars
Star formation
out of already
present frozen
gas balls took
place in phases
Helix planetary nebula
• Star exploded
• Became white dwarf
• Ca 40.000 “cometary
knots”
• = proto-gas balls
• Ca 1 earth mass
• Galactic dark matter
= gas balls of earth
mass: Macho’s
NGC-2623: Two galaxies inside each others dark matter?
Jeans clusters warmed: new stars in young star clusters
Antennae galaxies:
Two colliding galaxies
come within each others
dark matter sphere.
Along their trajectories
they transform several
cold Jeans clusters into
young globular star
clusters.
• Part 2: Cluster
dark matter
• Abell 1689 cluster
of galaxies
“Nearby” z = 0.184
• Einstein ring
Incomplete
Einstein ring
at 100/h kpc
Abell 1689
Center
Everything
is in circles:
Dark Matter
acts as
crystal ball
Incomplete
Einstein ring
at 143 kpc
Abell 1689
Centrum
Dark Matter
acts as
crystal ball
right: oldest galaxy 12.8 billion year
Hubble, after last repair May 2009
Cluster of
galaxies
Abell 370
Strongest
gravitation
lens
20 times
stronger
than
A1689
Description of lensing data of Abell 1689
Th.M. N. ’09: Consider quantum particles (fermions)
in each others gravitation at a certain temperature.
Measure
for
local
mass
density
Limousin et al, ApJ 2007
Tyson and Fischer ApJ 1995
distance to center
Neutrinos cause this lensing
•
•
•
•
Known particles: proton, electron, neutron, photon
Neutrino “little neutron”: neutral particle
Predicted in 1930 by Wolfgang Pauli
Lightest of all particles (not massless!)
• Mass now predicted with help of Abell 1689 cluster:
m  1,5 eV  2,7 1036 kg
• Mass between 0,2 eV and 2 eV will be searched
in Karlsruhe (2012)

Biggest quantum structure in the Universe
normalized density:
# neutrino’s
per cubic thermal length
per degree of freedom
distance to center
N>1: quantum degenerate
N=1: transition quantum-classical
At r = 505 kpc = 1.6 million lightyear
d = 2r
= 3.2 million lightyear
That is pretty large …
Incomplete
Einstein ring
at 143 kpc
Abell 1689
Center
Summary
Two kinds: Oort and Zwicky Dark Matter
• Oort Dark matter:
• Dark matter of galaxies is normal matter. Frozen gas balls of
earth mass (MACHO’s) in Jeans clusters of ca 100.000 solar
masses.
• Ca 100 million of those clusters in our Galaxy.
149 visible as old globular star cluster.
• Star formation in globular clusters explained: new stars
formed out of frozen gas balls that are already present.
• Dwarf galaxy problem (10.000 stars, much dark matter)
solved: Jeans cluster with still many frozen gas balls.
Summary
• Oort Dark Matter in galaxies
• Zwicky Dark Matter in clusters of galaxies:
• “new” particle: neutrino with mass of 1,5 eV (WIMP)
• Many searches for all kinds of heavy particles were in vain:
mass = keV, MeV, GeV, TeV, PeV
ADMX, ANAIS, ArDM, ATIC, BPRS, CAST, CDMS, CLEAN, CRESST,CUORE,
CYGNUS, (DAMA), DEEP, DRIFT, EDELWEISS, ELEGANTS, EURECA,
GENIUS, GERDA, GEDEON, GLAST, HDMS, IGEX, KIMS, LEP, LHC, LIBRA,
LUX, NAIAD, ORPHEUS, PAMELA, PICASSO, ROSEBUD, SIGN, SIMPLE,
UKDM, XENON, XMASS, ZEPLIN. DAMIC, FERMI, ICECUBE, VERITAS.
• Neutrino mass between 0,2 eV and 2 eV is searched
in Katrin experiment in Karlsruhe (2012).
Gravitational hydrodynamics of large scale structure formation
Th. M. N., Carl H. Gibson, Rudy E. Schild
arXiv:0906.5087
Do non-relativistic neutrinos constitute the dark matter?
Th. M. N.
Europhysics Letters 86 (2009) 59001
Psalm 118:22
The stone which the builders refused
is become the head stone of the corner
KArlsruhe TRItium Neutrino Experiments