Fast growth of supermassive black holes in galaxies

Abstract

Abstract. We report on a calculation of the growth of the mass of supermassive black holes at galactic centers from dark matter and Eddington -limited baryonic accretion. Assuming that dark matter halos are made of fermions and harbor compact degenerate Fermi balls of masses from 10 3 M to 10 6 M , we find that dark matter accretion can boost the mass of seed black holes from about ∼5 M to 10 3−4 M black holes, which then grow by Eddington-limited baryonic accretion to supermassive black holes of 10 6−9 M . We then show that the formation of the recently detected supermassive black hole of 3 × 10 9 M at a redshift of z = 6.41 in the quasar SDSS J114816.64+525150.3 could be understood if the black hole completely consumes the degenerate Fermi ball and then grows by Eddington-limited baryonic accretion. In the context of this model we constrain the dark matter particle masses to be within the range from 12 keV/c 2 to about 450 keV/c 2 . Finally we investigate the black hole growth dependence on the formation time and on the mass of the seed black hole. We find that in order to fit the observed data point of M BH ∼ 3 × 10 9 M and z ∼ 6.41, dark matter accretion cannot start later than about 2 × 10 8 years and the seed BH cannot be greater than about 10 4 M . Our results are in full agreement with the WMAP observations that indicate that the first onset of star formation might have occurred at a redshift of z ∼ 15−20. For other models of dark matter particle masses, corresponding constraints may be derived from the growth of black holes in the center of galaxies.

Sterile neutrino states

“…The experimental limits exist only for the larger mixing angles [3]. To explain the neutrino masses inferred from the atmospheric and solar neutrino experiments, n = 2 singlets are sufficient [4], but a greater number is required if the lagrangian (1) is to explain the LSND [5], the r-process nucleosynthesis [6], the pulsar kicks [7,8], dark matter [9,10,11,12], and the formation of supermassive black holes [13]. The scale of the right-handed Majorana masses M a is unknown; it can be much greater than the electroweak scale [2], or it may be as low as a few eV [5,14].…”

Dark Matter and Sterile Neutrinos

“…The lower limit could be improved to about 7 keV if the Fermi Dirac distribution is used in solving the Poisson's equation for the gravitational pontential of sterile neutrinos. 59,61 This graph has been taken from ref. 60 our Galaxy.…”

“…I then argue that the constrained particle could be the long sought dark matter of the Universe that is interpreted as a sterile neutrino. [59][60][61] The limits on the sterile neutrino mass are shown in Fig. 2. • Ruchayskiy, Oleg: Search for the light dark matter with an X-ray spectrometer Sterile neutrinos with the mass in the keV range are interesting warm dark matter (WDM) candidates.…”

A search for sterile neutrinos in MINOS

“…H is the Higgs doublet and L α (α = e, µ, τ ) are the lepton doublets. Current interest in sterile neutrinos stems from the fact that n = 2 singlets are sufficient to explain the neutrino masses from atmospheric and solar neutrino experiments, but more are needed to explain LSND [36], r-process nucleosynthesis [37], pulsar kicks [38,39], dark matter [41,42,43,44] and the formation of supermassive black holes [45]. A sterile neutrino hypothesis can explain these phenomena.…”