---
_id: '4283'
article_processing_charge: No
author:
- first_name: Nicholas H
  full_name: Barton, Nicholas H
  id: 4880FE40-F248-11E8-B48F-1D18A9856A87
  last_name: Barton
  orcid: 0000-0002-8548-5240
citation:
  ama: Barton NH. The geometry of adaptation. <i>Nature</i>. 1998;395(6704):751-752.
    doi:<a href="https://doi.org/10.1038/27338">10.1038/27338</a>
  apa: Barton, N. H. (1998). The geometry of adaptation. <i>Nature</i>. Nature Publishing
    Group. <a href="https://doi.org/10.1038/27338">https://doi.org/10.1038/27338</a>
  chicago: Barton, Nicholas H. “The Geometry of Adaptation.” <i>Nature</i>. Nature
    Publishing Group, 1998. <a href="https://doi.org/10.1038/27338">https://doi.org/10.1038/27338</a>.
  ieee: N. H. Barton, “The geometry of adaptation,” <i>Nature</i>, vol. 395, no. 6704.
    Nature Publishing Group, pp. 751–752, 1998.
  ista: Barton NH. 1998. The geometry of adaptation. Nature. 395(6704), 751–752.
  mla: Barton, Nicholas H. “The Geometry of Adaptation.” <i>Nature</i>, vol. 395,
    no. 6704, Nature Publishing Group, 1998, pp. 751–52, doi:<a href="https://doi.org/10.1038/27338">10.1038/27338</a>.
  short: N.H. Barton, Nature 395 (1998) 751–752.
date_created: 2018-12-11T12:08:02Z
date_published: 1998-10-01T00:00:00Z
date_updated: 2022-08-24T13:50:49Z
day: '01'
doi: 10.1038/27338
extern: '1'
fulldoi: https://doi.org/10.1038/27338
intvolume: '       395'
issue: '6704'
language:
- iso: eng
month: '10'
oa_version: None
page: 751 - 752
publication: Nature
publication_identifier:
  issn:
  - 0028-0836
publication_status: published
publisher: Nature Publishing Group
publist_id: '1802'
quality_controlled: '1'
scopus_import: '1'
status: public
title: The geometry of adaptation
type: review
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 395
year: '1998'
...
---
OA_place: repository
OA_type: green
_id: '17839'
abstract:
- lang: eng
  text: 'We study the observational signatures of a potential population of low-luminosity
    quasars at high redshifts in a ΛCDM cosmology. We derive the evolution of the
    quasar luminosity function at fainter luminosities and higher redshifts than currently
    detected based on three assumptions: (1) the formation of dark matter halos follows
    the Press-Schechter theory, (2) the ratio of central black hole mass to halo mass
    is the same for all halos, and (3) the light curve of quasars, in Eddington units,
    is universal. We show that a universal light curve provides an excellent fit to
    the observed quasar luminosity function at redshifts 2.6 < z < 4.5. By extrapolating
    the evolution of this luminosity function to higher redshifts (4.5 < z < 20),
    we find that the associated early population of low-luminosity quasars reionizes
    the universe at a redshift z ~ 12. The reprocessing of the UV light of these quasars
    by dust from early Type II supernovae distorts the microwave background spectrum
    by a Compton y-parameter y ~ 10-5, comparable to the lower limit set by COBE.
    The Next Generation Space Telescope could detect tens of quasars per arcmin-2
    from redshifts z > 10 with its proposed 1 nJy sensitivity at 1-3.5 μm. Absorption
    spectra of several such quasars would reveal the reionization history of the universe.'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
  orcid: 0000-0003-3633-5403
- first_name: Abraham
  full_name: Loeb, Abraham
  last_name: Loeb
citation:
  ama: Haiman Z, Loeb A. Observational signatures of the first quasars. <i>The Astrophysical
    Journal</i>. 1998;503(2):505-517. doi:<a href="https://doi.org/10.1086/306017">10.1086/306017</a>
  apa: Haiman, Z., &#38; Loeb, A. (1998). Observational signatures of the first quasars.
    <i>The Astrophysical Journal</i>. American Astronomical Society. <a href="https://doi.org/10.1086/306017">https://doi.org/10.1086/306017</a>
  chicago: Haiman, Zoltán, and Abraham Loeb. “Observational Signatures of the First
    Quasars.” <i>The Astrophysical Journal</i>. American Astronomical Society, 1998.
    <a href="https://doi.org/10.1086/306017">https://doi.org/10.1086/306017</a>.
  ieee: Z. Haiman and A. Loeb, “Observational signatures of the first quasars,” <i>The
    Astrophysical Journal</i>, vol. 503, no. 2. American Astronomical Society, pp.
    505–517, 1998.
  ista: Haiman Z, Loeb A. 1998. Observational signatures of the first quasars. The
    Astrophysical Journal. 503(2), 505–517.
  mla: Haiman, Zoltán, and Abraham Loeb. “Observational Signatures of the First Quasars.”
    <i>The Astrophysical Journal</i>, vol. 503, no. 2, American Astronomical Society,
    1998, pp. 505–17, doi:<a href="https://doi.org/10.1086/306017">10.1086/306017</a>.
  short: Z. Haiman, A. Loeb, The Astrophysical Journal 503 (1998) 505–517.
date_created: 2024-09-06T12:16:27Z
date_published: 1998-08-20T00:00:00Z
date_updated: 2024-11-13T07:43:28Z
day: '20'
doi: 10.1086/306017
extern: '1'
external_id:
  arxiv:
  - astro-ph/9710208
fulldoi: https://doi.org/10.1086/306017
intvolume: '       503'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.astro-ph/9710208
month: '08'
oa: 1
oa_version: Preprint
page: 505-517
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: American Astronomical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: Observational signatures of the first quasars
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 503
year: '1998'
...