Transcript Neutrino hot dark matter and hydrodynamics of structure formation

Neutrino hot dark matter and
hydrodynamics of structure formation:
Two “new” features of matter
Dr. Theo M. Nieuwenhuizen
Institute for Theoretical Physics
University of Amsterdam
Harvard Smithsonian
Center for Astrophysics
22 Jan 2010
Outline
Two types of dark matter
A modeling of lensing in Abell 1689
Mass, properties, name of DM particle
Dark matter condensation on cluster; reionization
Galactic dark matter: Gravitational hydrodynamics
The two types of dark matter
• Total mass of Universe: 4-5% baryons,
20-25 % dark matter,
•
70-75% dark energy
• Galactic dark mater: Oort 1931
Detected by rotation curves, dwarf galaxies
• MACHOs: Massive Astrophysical Compact Halo Objects:
Hydrodynamics: Milli Brown Dwarfs consisting of baryons
• Cluster dark matter: Zwicky 1932
Detected from rotation curves, by lensing
• WIMPs Weakly Interacting Massive Particles
• The dark matter of galaxy clusters is non-baryonic.
• Not MACHOs or WIMPs but MACHOs and WIMPs !!
• Abell 1689
galaxy cluster
• Nearby z = 0.184
• Total mass
1  3 1015 M 
• Luminous mass
4.4 1011 M 
• Baryon poor
• Einstein ring
Incomplete
Einstein ring
at 100/h kpc
Abell 1689
Center
Dark matter
acts as
crystal ball
Abell 1689
X-ray
emitting gas
T=10 keV =
1.16 10^8 K
Three
components:
Dark matter
Galaxies
Gas
Hubble, after last repair May 2009
Galaxy
cluster
Abell 370
Strongest
gravitation
lens:
20 times
stronger
than A1689
Theory
Cowsik&McClelland 1973
Treumann,Kull&Bohringer 2000
Nieuwenhuizen 2009
• Assume that DM comes from non-interacting fermions
in their common gravitational potential
• Mass m, degeneracy g; g = 2 (2s+1) #families
• Isothermal model for fermions
• Isothermal model for Galaxies and X-ray gas
• Virial equilibrium:
• 30% solar metallicity
Fit to A1689 lensing data of Tyson and Fischer ApJ 1995
Limousin et al, ApJ 2007
average
projected
mass
radius
The mass of the dark matter particle
small statistical error 2%
reduced Hubble parameter
= number of available modes in cluster
Previous estimates and searches: keV, MeV, GeV, TeV: excluded
Additional CDM component: excluded
What is the dark matter particle?
The dark matter fraction
Early decouplers have small g: Not gravitinos, neutralinos, X-inos
Not bosons, e.g. axions
Match possible to WMAP5
for
(anti) neutrinos, left+right-handed, 3 families: g = 2*2*3=12
=12
mass = 1.45 eV
Neutrino oscillations cause small mass differences, 0.001 eV or less
SuperNovae Riess 09: h=0.74,
Macrolensing: h=0.65
Neutrinos in the cluster
Thermal length visible to the eye
Temperature is low
Smaller than would-be momentum temperature T_p=1.95 K
Larger than would-be energy temperature T_E=0.0001 K
Typical speed is non-relativistic,
v = 490 km/s
Local density can be enormous:
in Abell center: one billion in a few cc
The biggest quantum structure
in the Universe
normalized density:
# neutrinos
per cubic thermal wavelength
per degree of freedom
N>1: quantum degenerate nu’s
N=1: quantum-to-classical crossover
at r = 505 kpc = 1.6 million light year
d = 2r
= 3.2 million light year
That is pretty big …
Incomplete
Einstein ring
at 100/h kpc
Abell 1689
Center
Temperature of gas: 10 keV=10^8 K
Virial T of alpha-particles
overlaps with it.
Log(Mass)
Virial equilibrium assumed;
only amplitude adjusted
Log(r/kpc)
Cluster radiates in X-rays like a star in light.
Radiated energy supplied by contraction, as in stars.
Radiation helps to maintain virial equilibrium.
Why isothermal (virial) equilibrium?
• Lynden Bell: violent relaxation, faster than collisional
• Relaxation in time-dependent potential:
every object (individual particle, galaxy) exchanges
energy with the whole cluster
• Iff phase space density becomes uniform, then
Fermi-Dirac distribution
• X-ray radiation helps to maintain the virial state,
as in the sun
CDM or HDM?
• Cold Dark Matter: heavy particles already clumped at decoupling z=1100
• But light neutrinos are free streaming until trapped by galaxy cluster
• Free streaming
• Crossover when Newton force of baryons matches Hubble force Hp: z = 6 - 7
• Then cosmic voids loose neutrinos and become empty
• This heats the intracluster gas up to 10 keV, so it reionizes, without heavy stars
• Hot Dark Matter paradigm agrees with gravito-hydrodynamics
Gravitational hydrodynamics
• At decoupling: photon mean free path = 10^(-5) pc << horizon
(Silk damping)
• Step 1: In the plasma
• Effect of viscosity important below z = 5000
• Instability in plasma: proto-voids & proto-galaxy-clusters
• Size of proto-voids*(z+1) = 40 Mpc now
• 13.6 eV recombination energy gives CMB T-fluctuations
of sub-Kelvin
Milky Way
region in Crux
Gravitational hydrodynamics II
• At decoupling: galaxies; Jeans clusters 40,000 solar mass
• Some Jeans clusters developed into globular star clusters
Others were used for ordinary stars
• Most still exist and are dark. These Jeans clusters act as isothermal
“particles” forming the galactic dark matter
• Explains flattening rotation curves, Tully Fisher relation
• Explains galaxy mergers
• Milli-lensing “CDM” subhalos explained as Jeans clusters
• (Dwarf) galactic DM does NOT exclude neutrino DM
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.
NGC-2623: Two galaxies inside each others dark matter?
Jeans clusters warmed: new stars in young star clusters
Tadpole galaxy (HST)
Gravitational hydrodynamics III
• At decoupling: fragmentation of Jeans clusters in
milli brown dwarfs (MBDs) of terrestrial weight.
• Thousands of frozen MBDs observed in microlensing
at unit optical depth (Schild 1996, 1999)
• 40,000 of heated MBDs in planetary nebulae counted in Spitzer
infrared. Connected to hydrodynamics by Gibson&Schild 98-08
• Extreme Scattering Events: Earth-Jovian gas clouds observed in
radio. Walker&Wardle 98: May be good fraction of galactic mass
• Multiple imaging of pulsars: by MBDs in Jeans clusters
• Explanation of H-alpha forest absorption lines
Helix planetary nebula
Star exploded
Became white dwarf
Ca 40.000 “cometary
knots” in radio
= proto-gas balls
Ca 1 earth mass
Galactic dark matter
= gas balls of earth
mass: Macho’s
Summary
• Observed DM of Abell 1689 cluster explained by thermal fermions of eV mass.
keV, MeV, GeV, TeV, PeV excluded. Thermal bosons (axions) excluded.
• Fitting with global dark matter fraction: 6 active + 6 sterile (anti-)neutrinos
Mass about 1.45 eV, depends on h
• Gas temperature 10^8 K = alpha-particle temp., gas profile matches automatically
• Free flow into potential well occurs at z = 6 - 7. Causes reionization,
without heavy stars
• Neutrino Hot Dark Matter challenges Cold Dark Matter (CDM).
• Dark matter particle was not (and should not be) observed in searches
•
ADMX, ANAIS, ArDM, ATIC, BPRS, CAST, CDMS, CLEAN, CRESST, CUORE, CYGNUS, (DAMA),
DAMIC, DEEP, DRIFT, EDELWEISS, ELEGANTS, EURECA, GENIUS, GERDA, GEDEON, FERMIGLAST, HDMS, ICECUBE, IGEX, KIMS, LEP, LHC, LIBRA, LUX, NAIAD, ORPHEUS, PAMELA,
PICASSO, ROSEBUD, SIGN, SIMPLE, UKDM, VERITAS, XENON, XMASS, ZEPLIN. AMANDA,
ANTARES, EGRET.
• Neutrino mass tested in 2015 in Katrin search between 0.2 eV – 2 eV
Summary II
• Hydrodynamics is important before and at decoupling
• Predicts structure formation from baryons without CDM trigger
• Explains a wealth of observations
• Hydrodynamic structure formation is top-down
• So CDM cannot be right and its particle has not been found
• Even for the CMB peaks, it offers no explanation for the scatter of
unbinned data, or for the regime l=3000-8000. Turbulence does.
• Hydrodynamics connects structure formation to turbulence.
Do non-relativistic neutrinos constitute the dark matter?
Th. M. N.
Europhysics Letters 86 (2009) 59001
Gravitational hydrodynamics of large-scale structure formation
Th. M. N., Carl H. Gibson, Rudy E. Schild
Europhysics Letters 88 (2009) 49001
Psalm 118:22
The stone which the builders refused
is become the head stone of the corner
KArlsruhe TRItium Neutrino Experiments