---
_id: '17786'
abstract:
- lang: eng
  text: "The first stars and black holes that formed in the Universe are likely too
    faint for a direct detection. However, by ionizing most of the intergalactic medium
    (IGM), they left an indirect clue that reveals their existence. We discuss currently
    available observational constraints on the reionization history of IGM, and the
    extent to which accreting black holes (BHs) and stars can help account for these
    observations. We argue, based on the combined statistics of Lyman α and β absorption
    in quasar spectra, that the IGM contains a significant amount of neutral hydrogen
    with nHI/nH ≳0.1. On the other hand, we argue, based on the lack of a strong evolution
    in the observed abundance of Lyman α emitting galaxies beyond z ∼5.5, that the
    mean neutral hydrogen fraction cannot exceed nHI/nH ≈0.3 at the same redshift.
    We conclude that the IGM is experiencing rapid ionization at redshift z ∼6.\r\nWe
    find that quasar BHs, including faint ones that are individually below the detection
    thresholds of existing optical and X-ray surveys, are unlikely to drive the evolution
    of the neutral fraction around this epoch, because they would over-produce the
    present-day soft X-ray background. On the other hand, the seeds of the z ∼6 quasar
    BHs likely appeared at much earlier epochs (z ∼20), and produced hard ionizing
    radiation by accretion. These early BHs are promising candidates to account for
    the high redshift (z ∼15) ionization implied by the recent cosmic microwave anisotropy
    data from WMAP.\r\nUsing a model for the growth of BHs by accretion and mergers
    in a hierarchical cosmology, we suggest that the early growth of quasars must
    include a super-Eddington growth phase, and that, although not yet optically identified,
    the FIRST radio survey may have already detected several thousand > 10^8 M⊙ BHs
    at z > 6."
article_processing_charge: No
article_type: original
author:
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
citation:
  ama: Haiman Z. Finding the first generation of stars and black holes. <i>Progress
    of Theoretical Physics Supplement</i>. 2005;158:86-104. doi:<a href="https://doi.org/10.1143/ptps.158.86">10.1143/ptps.158.86</a>
  apa: Haiman, Z. (2005). Finding the first generation of stars and black holes. <i>Progress
    of Theoretical Physics Supplement</i>. Oxford University Press. <a href="https://doi.org/10.1143/ptps.158.86">https://doi.org/10.1143/ptps.158.86</a>
  chicago: Haiman, Zoltán. “Finding the First Generation of Stars and Black Holes.”
    <i>Progress of Theoretical Physics Supplement</i>. Oxford University Press, 2005.
    <a href="https://doi.org/10.1143/ptps.158.86">https://doi.org/10.1143/ptps.158.86</a>.
  ieee: Z. Haiman, “Finding the first generation of stars and black holes,” <i>Progress
    of Theoretical Physics Supplement</i>, vol. 158. Oxford University Press, pp.
    86–104, 2005.
  ista: Haiman Z. 2005. Finding the first generation of stars and black holes. Progress
    of Theoretical Physics Supplement. 158, 86–104.
  mla: Haiman, Zoltán. “Finding the First Generation of Stars and Black Holes.” <i>Progress
    of Theoretical Physics Supplement</i>, vol. 158, Oxford University Press, 2005,
    pp. 86–104, doi:<a href="https://doi.org/10.1143/ptps.158.86">10.1143/ptps.158.86</a>.
  short: Z. Haiman, Progress of Theoretical Physics Supplement 158 (2005) 86–104.
date_created: 2024-09-06T10:19:04Z
date_published: 2005-02-01T00:00:00Z
date_updated: 2024-09-30T13:00:29Z
day: '01'
doi: 10.1143/ptps.158.86
extern: '1'
intvolume: '       158'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1143/PTPS.158.86
month: '02'
oa: 1
oa_version: Published Version
page: 86-104
publication: Progress of Theoretical Physics Supplement
publication_identifier:
  issn:
  - 0375-9687
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Finding the first generation of stars and black holes
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 158
year: '2005'
...