---
res:
  bibo_abstract:
  - 'We discuss a simple model for the growth of supermassive black holes (BHs) at
    the center of spheroidal stellar systems. In particular, we assess the hypotheses
    that (1) star formation in spheroids and BH fueling are proportional to one another,
    and (2) the BH accretion luminosity stays near the Eddington limit during luminous
    quasar phases. With the aid of this simple model, we are able to interpret many
    properties of the QSO luminosity function, including the puzzling steep decline
    of the characteristic luminosity from redshift z=2 to to z=0: indeed the residual
    star formation in spheroidal systems is today limited to a small number of bulges,
    characterized by stellar velocity dispersions a factor of 2-3 smaller those of
    the elliptical galaxies hosting QSOs at z > 2. A simple consequence of our hypotheses
    is that the redshift evolution of the QSO emissivity and of the star formation
    history in spheroids should be roughly parallel. We find this result to be broadly
    consistent with our knowledge of the evolution of both the global star formation
    rate, and of the evolution of the QSO emissivity, but we identify interesting
    discrepancies at both low and high redshifts, to which we offer tentative solutions.
    Finally, our hypotheses allow us to present a robust method to derive the duty
    cycle of QSO activity, based on the observed QSO luminosity function, and on the
    present-day relation between the masses of supermassive BHs and those of their
    spheroidal host stellar systems. The duty cycle is found to be substantially less
    than unity, with characteristic values in the range (3-6)x10^(-3), and we compute
    that the average bolometric radiative efficiency is epsilon=0.07. Finally, we
    find that the growth in mass of individual black holes at high redshift (z>2)
    can be dominated by mergers, and is therefore not necessarily limited by accretion.@eng'
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Zoltán
      foaf_name: Haiman, Zoltán
      foaf_surname: Haiman
      foaf_workInfoHomepage: http://www.librecat.org/personId=7c006e8c-cc0d-11ee-8322-cb904ef76f36
  - foaf_Person:
      foaf_givenName: Luca
      foaf_name: Ciotti, Luca
      foaf_surname: Ciotti
  - foaf_Person:
      foaf_givenName: Jeremiah P.
      foaf_name: Ostriker, Jeremiah P.
      foaf_surname: Ostriker
  bibo_doi: 10.1086/383022
  bibo_issue: '2'
  bibo_volume: 606
  dct_date: 2004^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0004-637X
  - http://id.crossref.org/issn/1538-4357
  dct_language: eng
  dct_publisher: American Astronomical Society@
  dct_title: 'Reasoning from fossils: Learning from the local black hole population
    about the evolution of quasars@'
...