NEUTRINO MASSES DARK MATTER AND THE MYSTERIOUS EARLY
- Slides: 19
NEUTRINO MASSES DARK MATTER AND THE MYSTERIOUS EARLY QUASARS R. D. Viollier University of Cape Town
The Mysterious Early Quasars Observational facts: Earliest quasar SDSS J 114816. 64 +525 150. 3 has redshift z = 6. 42 corresponding to receding velocity v/c = 0. 96. Quasar light was emitted at te = 0. 85 Gyr and is observed today at to = 13. 7 Gyr after the Big Bang (WMAP-3). Simplest interpretation: Quasar is temporarily (Δt < 30 Myr) powered by isotropic accretion of baryonic matter onto a supermassive black hole of mass M = 3× 109 M☼, radiating at the Eddington luminosity
The Eddington Luminosity gravitational force on protons dominates M(r) - mass enclosed within r mp proton mass radiational force on electrons dominates σT - Thomson cross section of the electron LE(r) - nett luminosity crossing r outwards
The Eddington Luminosity cont. local neutrality of plasma implies Fgrav(r) = Frad(r) or Eddington luminosity
Black Hole Mass Increase differential equation εM = 0. 1 is the standard efficiency εL = L/LE = 1 for the Eddington limit Eddington time characteristic time solution mass doubling time Answer: 210 ~ 103 230 ~ 109 30 mass doubling times t = 30 × 35 Myr = 1. 05 Gyr
S N c r e t i o n Simplest Scenario for the formation of supermassive black holes o e x p l massive staros ~ 25 M⊙ i o n f stellar mass BH ~ 3 M⊙ b a r y o n i c supermassi ve BH ~ 3× 109 M⊙ HOWEVER: m Compare this tform > 1. 437 • the massive star can only form Gyr to the after zreion ~ 11 or treion ~ 0. 365 Gyr a t t e observed r times of te ~ 0. 85 Gyr this scenario does not work! reionization molecular hydrogen
Three possible remedies initial BH mass should be MBH(0) = 1. 4× 105 M☼ instead of MBH(0) = 3 M☼ population III stars? allowing super-Eddington accretion with e. g. εL = 2 instead of εL = 1 non-spherical accretion? lowering the efficiency from εM = 0. 1 to εM = 0. 05 (dark matter has εM = 0!) X X √
ν-Minimal Extension of the Standard Model P. Minkowski, Phys. Lett. B 67 (1977) 421: add 3 right-handed (or sterile) neutrinos invention of the seesaw mechanism renormalizable Lagrangean which generates Dirac and Majorana masses for all neutrinos kinetic energy Yukawa terms coupling Majorana mass MD = FαI ‹Ф›exp terms MI
Discussion of the νMSM In comparison with the SM, the νMSM has 18 new parameters: 18 new parameters of νMSM 3 Majorana masses of NI 15 Yukawa couplings in leptonic sector 3 Dirac masses 6 mixing angles 6 CP-violating phases these parameters can be chosen such as to be consistent with the solar, atmospheric, reactor and accelerator neutrino experiments the baryon asymmetry comes out correctly the Majorana masses are below the weak interaction symmetry breaking scale the lowest mass right-handed (or sterile) neutrino has a mass of O(10 ke. V) and is quasi-stable: it could be the dark matter particle
Spectrum of the νMSM unstable, observable at accelerators M. Shaposhnikov arxiv: 0706. 1894 v 1 [hep-ph] 13. 06. 2007 quasi-stable dark matter particle, observable through its radioactive decay
Properties of N 1 ≡ νs to fix our ideas, we assume production process: scattering that the lightest sterile of active neutrinos out of neutrino νs has equilibrium Majorana mass • m = 15 mixing: resonant or non -resonant ≡ vacuum L. Wolfenstein (1978) ke. V/c 2 Mixing angle of νs with νe • ϑ = 10 -6. 5 Lepton asymmetry • L(νe) = (n(νe) – n( νe))/n(γ) = 10 -2 production process is number densities of νe, γ necessarily linked with decay • n(νe), n(γ) process!
Early Cosmology νs’s produced at T ~ 328 (mc 2/15 ke. V)1/3 Me. V/K with Ωs= 0. 24 through resonant and non-resonant scattering of active neutrinos ~ 22 min after Big Bang, the νs’s are non-relativistic νs’s dominate the expansion of the universe ~ 79 kyr after Big Bang degenerate νs-balls form between 650 Myr and 840 Myr
Mass Limits of νs-balls mass contained within the free-streaming length at matter-radiation equality at 79 kyr is resonant production, cold non-resonant production, warm since part of the neutrinos may be ejected, the minimal mass that may collapse is perhaps Mmin ~ 106 M☼. the maximal mass that a self-gravitating degenerate neutrino ball can support is the Oppenheimer-Volkoff limit Planck mass m-dependent
Symbiotic Scenario NEW for the formation of supermassive black holes NEW supermas sive νsball 650 Myr < t < 840 Myr attraction of H 2 cloud to center of νs-ball M. C. Richter, G. B. Tupper, R. D. Viollier S N JCAP 0612 (2006) 015; astro-ph/0611552 5 supermas massive EW N stellar M sive BH star y mass BH through r M ~ 25 accretion M ~ 3 M⊙ M⊙ of νs-ball antihierarchical formation of quasars and active galactic nuclei
Accretion of a Neutrino Halo onto a Black Hole Bernoulli’s equation for a steady Bernoulli’s equation is now Here, v(x) fulfils the Lane-Emden -state flow • u(r): • v. F(r): • φ(r): • r. H: flow velocity of infalling degenerate sterile neutrino fluid Fermi velocity gravitational potential radius of the halo the flow is trans-sonic, i. e. equation
Accretion continued Total mass enclosed within a radius r = bx is Solutions of the Lane-Emden equation with constant mass M = MC + MH = 2. 714 M⊙
Accretion continued mass accretion rate into a sphere, containing a mass MC within a radius r. C from the centre is μ = MC /M with universal time scale and shut-off parameter, defined as r. C = bx. C is now the radius at which the escape velocity is c
Results M. C. Richter, G. B. Tupper, R. D. Viollier JCAP 0612 (2006) 015; astro-ph/0611552
Conclusions 4 main characteristics of the symbiotic scenario: no Eddington limit for νs-ball formation and accretion onto BH matter densities in νs-balls much larger than any form of baryonic matter of the same total mass νs-balls have for m ~15 ke. V/c 2 the same mass range as supermassive BH different escape velocities from the center of the νs-balls may explain antihierarchical formation of quasars
- Dark matter and dark energy presentation
- Neutrino interaction with matter
- In a dark dark town
- Dark matter gravitons dimensions
- Boosted dark matter
- Dark matter
- Dark matter pwo
- Dark matter physics
- Where to stream dark matter
- What could dark matter be
- Cindms
- Dark matter
- Dark matter
- Les houches dark matter
- Early cpr and early defibrillation can: *
- Dotterkärna
- Leptons
- Lepton number
- Neutrino
- Neutrino