The BlackHole Halo Mass Relation and High Redshift Quasars

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The Black-Hole Halo Mass Relation and High
Redshift Quasars
Fan et al. (2001)
-SMBHs and dark matter halos -SMBHs and
quasars -The quasar correlation
function -Extending the SMBH -- halo relation to
earlier times. Is dark matter halo mass or
velocity more important for formation?

• Stuart Wyithe Avi Loeb
• (The University of Melbourne)
  (Harvard University)

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Black-Hole Dark-Matter Halo Masses

• The bulges of all local galaxies contain SMBHs.
• There is a tight relation between ? and SMBH mass
  (e.g. Merritt Ferrarese 2001
  Tremaine et al. 2002).
• There is a relation between ? and vhalo, and
  hence a relation between SMBH and dark matter
  halo mass.

Ferrarese (2002)
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How is the SMBH Related to its Host Halo at
Larger Redshifts?

• Both Mbhvhalo5 and MbhMhalo5/3 valid at z0.
• At higher redshift, galaxies form out of a denser
  background, have a larger binding energy per unit
  mass, and therefore a larger circular velocity.
• Is halo mass or velocity the determining factor?

Three assumptions
SMBH mass dependent on halo mass
SMBH mass dependent on halo velocity
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Quasars

• Quasars are powered by accretion onto a SMBH.
• The velocity dispersion -- SMBH mass relation is
  also seen in quasars. (e.g. McLure Dunlop 2002)
• Accretion is near the Eddington Rate.
  
  (e.g. Willott et al. 2003 Elvis et al. 1994)

Boyle et al. (2000)

• Quasars offer a pointer to the evolution of the
  SMBH population to z6.

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The Quasar Correlation Function.

• The quasar correlation function measures, as a
  function of distance R, the excess probability
  above random that two quasars will be separated
  by R.
• Larger halos are more highly clustered.
• The Mbh-Mhalo relation, and accretion at the
  Eddington rate relate luminosity to halo mass
  and therefore the quasar correlation function to
  the dark matter halo correlation function.

Three assumptions
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Large Scale Distribution of QuasarsFrom the 2dF
Quasar Redshift Survey

• Redshifts for 25,000 quasars in two strips.
• The correlation function tests the relation
  between luminosity and halo mass.

Croom et al. (2000,2001)
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Comparison with Observed Quasar Correlation
Function Assuming Mbh vhalo5
Croom et al. (2000,2001)
Correlation Length

• The correlation function is in agreement with
  quasars that shine near their limiting rate.

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Evolution of Clustering Length With Redshift and
Luminosity (Mbhvhalo5)
Preliminary SDSS data

• More luminous samples are more highly clustered.

• Clustering increases with redshift in a flux
  limited sample.

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What if MbhMhalo2/3 With No Redshift Dependence?
Preliminary SDSS data

• Black-holes comprise a larger fraction of a
  galaxies mass at earlier times

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The Correlation Length Favours Larger Mbh/Mhalo
at High Redshift

• No evolution in the Mbh-Mhalo relation implies
  Super-Eddington accretion at z3

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Summary

• The quasar clustering length and its evolution
  with redshift and luminosity are reproduced if
  SMBH mass scales only with halo circular
  velocity.
• The evolution of the clustering length is too
  rapid if SMBH mass scales only with halo mass.
• This may imply that the mass of a SMBH is
  regulated by the depth of the potential well of
  the galaxy.

Black-holes comprise a larger fraction of a
galaxies mass at high redshift