---
_id: '17717'
abstract:
- lang: eng
  text: We demonstrate that constraints on cosmological parameters from the distribution
    of clusters as a function of redshift (dN/dz) are complementary to accurate angular
    diameter distance (D_A) measurements to clusters, and their combination significantly
    tightens constraints on the energy density content of the Universe. The number
    counts can be obtained from X-ray and/or SZ (Sunyaev-Zel'dovich effect) surveys,
    and the angular diameter distances can be determined from deep observations of
    the intra-cluster gas using their thermal bremsstrahlung X-ray emission and the
    SZ effect. We combine constraints from simulated cluster number counts expected
    from a 12 deg^2 SZ cluster survey and constraints from simulated angular diameter
    distance measurements based on the X-ray/SZ method assuming a statistical accuracy
    of 10% in the angular diameter distance determination of 100 clusters with redshifts
    less than 1.5. We find that Omega_m can be determined within about 25%, Omega_Lambda
    within 20%, and w within 16%. We show that combined dN/dz + D_A constraints can
    be used to constrain the different energy densities in the Universe even in the
    presence of a few percent redshift dependent systematic error in D_A. We also
    address the question of how best to select clusters of galaxies for accurate diameter
    distance determinations. We show that the joint dN/dz + D_A constraints on cosmological
    parameters for a fixed target accuracy in the energy density parameters are optimized
    by selecting clusters with redshift upper cut--offs in the range 0.5 < z < 1.
article_processing_charge: No
article_type: original
author:
- first_name: Sandor M.
  full_name: Molnar, Sandor M.
  last_name: Molnar
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
- first_name: Mark
  full_name: Birkinshaw, Mark
  last_name: Birkinshaw
- first_name: Richard F.
  full_name: Mushotzky, Richard F.
  last_name: Mushotzky
citation:
  ama: Molnar SM, Haiman Z, Birkinshaw M, Mushotzky RF. Constraints on the energy
    content of the universe from a combination of galaxy cluster observables. <i>The
    Astrophysical Journal</i>. 2004;601(1):22-27. doi:<a href="https://doi.org/10.1086/380295">10.1086/380295</a>
  apa: Molnar, S. M., Haiman, Z., Birkinshaw, M., &#38; Mushotzky, R. F. (2004). Constraints
    on the energy content of the universe from a combination of galaxy cluster observables.
    <i>The Astrophysical Journal</i>. American Astronomical Society. <a href="https://doi.org/10.1086/380295">https://doi.org/10.1086/380295</a>
  chicago: Molnar, Sandor M., Zoltán Haiman, Mark Birkinshaw, and Richard F. Mushotzky.
    “Constraints on the Energy Content of the Universe from a Combination of Galaxy
    Cluster Observables.” <i>The Astrophysical Journal</i>. American Astronomical
    Society, 2004. <a href="https://doi.org/10.1086/380295">https://doi.org/10.1086/380295</a>.
  ieee: S. M. Molnar, Z. Haiman, M. Birkinshaw, and R. F. Mushotzky, “Constraints
    on the energy content of the universe from a combination of galaxy cluster observables,”
    <i>The Astrophysical Journal</i>, vol. 601, no. 1. American Astronomical Society,
    pp. 22–27, 2004.
  ista: Molnar SM, Haiman Z, Birkinshaw M, Mushotzky RF. 2004. Constraints on the
    energy content of the universe from a combination of galaxy cluster observables.
    The Astrophysical Journal. 601(1), 22–27.
  mla: Molnar, Sandor M., et al. “Constraints on the Energy Content of the Universe
    from a Combination of Galaxy Cluster Observables.” <i>The Astrophysical Journal</i>,
    vol. 601, no. 1, American Astronomical Society, 2004, pp. 22–27, doi:<a href="https://doi.org/10.1086/380295">10.1086/380295</a>.
  short: S.M. Molnar, Z. Haiman, M. Birkinshaw, R.F. Mushotzky, The Astrophysical
    Journal 601 (2004) 22–27.
date_created: 2024-09-06T09:02:16Z
date_published: 2004-01-20T00:00:00Z
date_updated: 2024-09-25T13:08:12Z
day: '20'
doi: 10.1086/380295
extern: '1'
intvolume: '       601'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1086/380295
month: '01'
oa: 1
oa_version: Published Version
page: 22-27
publication: The Astrophysical Journal
publication_identifier:
  issn:
  - 0004-637X
  - 1538-4357
publication_status: published
publisher: American Astronomical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: Constraints on the energy content of the universe from a combination of galaxy
  cluster observables
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 601
year: '2004'
...