The XMM-Newton wide-field survey in the COSMOS field. V angular clustering of the X-ray point sources

Takamitsu Miyaji, Giovanni Zamorani, Nico Cappelluti, Roberto Gilli, Richard E. Griffiths, Andrea Comastri, Günther Hasinger, Marcella Brusa, Fabrizio Fiore, Simonetta Puccetti, Luigi Guzzo, Alexis Finoguenov

Research output: Contribution to journalReview article

48 Citations (Scopus)

Abstract

We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the ∼2 deg 2 COSMOS field (COSMOS XMM-Newton). Significant positive signals have been detected in the 0.5-2 (SFT) band, in the angle range of 0.5′-24′, while the positive signals were at the ∼2 and ∼3 σ levels in the 2-4.5 (MED) and 4.5-10 (UHD) keV bands, respectively. Correctly taking integral constraints into account is a major limitation in interpreting our results. With power-law fits to the ACFs without the integral constraint term, we find correlation lengths of θ c = 1.9″ ± 0.3″ , 0.8″ -0.4″ +0.5″ and 6″ ± 2″ for the SFT, MED, and UHD bands, respectively, for γ = 1.8. The inferred comoving correlation lengths, also taking into account the bias by the source merging due to XMM-Newton PSF, are r c ≈ 9.8 ± 0.7, 5.8 -1.7 +1.4, and 12 ± 2 h -1 Mpc at the effective redshifts of z̄ eff ≈1.1, 0.9, and 0.6 for the SFT, MED, and UHD bands, respectively. If we include the integral constraint term in the fitting process, assuming that the power law extends to the scale length of the entire COSMOS XMM-Newton field, the correlation lengths become larger by ∼20%-90%. Comparing the inferred rms fluctuations of the spatial distribution of AGNs σ 8,AGN with those of the underlying mass, the bias parameters of the X-ray source clustering at these effective redshifts are in the range b AGN = 1.5-4.

Original languageEnglish (US)
Pages (from-to)396-405
Number of pages10
JournalAstrophysical Journal, Supplement Series
Volume172
Issue number1
DOIs
StatePublished - Oct 22 2007
Externally publishedYes

Fingerprint

XMM-Newton telescope
newton
point sources
field survey
point source
autocorrelation
power law
x rays
spatial distribution
COSMOS

Keywords

  • Galaxies: active
  • Quasars: general
  • X-rays: galaxies

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

The XMM-Newton wide-field survey in the COSMOS field. V angular clustering of the X-ray point sources. / Miyaji, Takamitsu; Zamorani, Giovanni; Cappelluti, Nico; Gilli, Roberto; Griffiths, Richard E.; Comastri, Andrea; Hasinger, Günther; Brusa, Marcella; Fiore, Fabrizio; Puccetti, Simonetta; Guzzo, Luigi; Finoguenov, Alexis.

In: Astrophysical Journal, Supplement Series, Vol. 172, No. 1, 22.10.2007, p. 396-405.

Research output: Contribution to journalReview article

Miyaji, T, Zamorani, G, Cappelluti, N, Gilli, R, Griffiths, RE, Comastri, A, Hasinger, G, Brusa, M, Fiore, F, Puccetti, S, Guzzo, L & Finoguenov, A 2007, 'The XMM-Newton wide-field survey in the COSMOS field. V angular clustering of the X-ray point sources', Astrophysical Journal, Supplement Series, vol. 172, no. 1, pp. 396-405. https://doi.org/10.1086/516579
Miyaji, Takamitsu ; Zamorani, Giovanni ; Cappelluti, Nico ; Gilli, Roberto ; Griffiths, Richard E. ; Comastri, Andrea ; Hasinger, Günther ; Brusa, Marcella ; Fiore, Fabrizio ; Puccetti, Simonetta ; Guzzo, Luigi ; Finoguenov, Alexis. / The XMM-Newton wide-field survey in the COSMOS field. V angular clustering of the X-ray point sources. In: Astrophysical Journal, Supplement Series. 2007 ; Vol. 172, No. 1. pp. 396-405.
@article{4ee7f651606349d1b933c5ac5d0df3a3,
title = "The XMM-Newton wide-field survey in the COSMOS field. V angular clustering of the X-ray point sources",
abstract = "We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the ∼2 deg 2 COSMOS field (COSMOS XMM-Newton). Significant positive signals have been detected in the 0.5-2 (SFT) band, in the angle range of 0.5′-24′, while the positive signals were at the ∼2 and ∼3 σ levels in the 2-4.5 (MED) and 4.5-10 (UHD) keV bands, respectively. Correctly taking integral constraints into account is a major limitation in interpreting our results. With power-law fits to the ACFs without the integral constraint term, we find correlation lengths of θ c = 1.9″ ± 0.3″ , 0.8″ -0.4″ +0.5″ and 6″ ± 2″ for the SFT, MED, and UHD bands, respectively, for γ = 1.8. The inferred comoving correlation lengths, also taking into account the bias by the source merging due to XMM-Newton PSF, are r c ≈ 9.8 ± 0.7, 5.8 -1.7 +1.4, and 12 ± 2 h -1 Mpc at the effective redshifts of z̄ eff ≈1.1, 0.9, and 0.6 for the SFT, MED, and UHD bands, respectively. If we include the integral constraint term in the fitting process, assuming that the power law extends to the scale length of the entire COSMOS XMM-Newton field, the correlation lengths become larger by ∼20{\%}-90{\%}. Comparing the inferred rms fluctuations of the spatial distribution of AGNs σ 8,AGN with those of the underlying mass, the bias parameters of the X-ray source clustering at these effective redshifts are in the range b AGN = 1.5-4.",
keywords = "Galaxies: active, Quasars: general, X-rays: galaxies",
author = "Takamitsu Miyaji and Giovanni Zamorani and Nico Cappelluti and Roberto Gilli and Griffiths, {Richard E.} and Andrea Comastri and G{\"u}nther Hasinger and Marcella Brusa and Fabrizio Fiore and Simonetta Puccetti and Luigi Guzzo and Alexis Finoguenov",
year = "2007",
month = "10",
day = "22",
doi = "10.1086/516579",
language = "English (US)",
volume = "172",
pages = "396--405",
journal = "Astrophysical Journal, Supplement Series",
issn = "0067-0049",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - The XMM-Newton wide-field survey in the COSMOS field. V angular clustering of the X-ray point sources

AU - Miyaji, Takamitsu

AU - Zamorani, Giovanni

AU - Cappelluti, Nico

AU - Gilli, Roberto

AU - Griffiths, Richard E.

AU - Comastri, Andrea

AU - Hasinger, Günther

AU - Brusa, Marcella

AU - Fiore, Fabrizio

AU - Puccetti, Simonetta

AU - Guzzo, Luigi

AU - Finoguenov, Alexis

PY - 2007/10/22

Y1 - 2007/10/22

N2 - We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the ∼2 deg 2 COSMOS field (COSMOS XMM-Newton). Significant positive signals have been detected in the 0.5-2 (SFT) band, in the angle range of 0.5′-24′, while the positive signals were at the ∼2 and ∼3 σ levels in the 2-4.5 (MED) and 4.5-10 (UHD) keV bands, respectively. Correctly taking integral constraints into account is a major limitation in interpreting our results. With power-law fits to the ACFs without the integral constraint term, we find correlation lengths of θ c = 1.9″ ± 0.3″ , 0.8″ -0.4″ +0.5″ and 6″ ± 2″ for the SFT, MED, and UHD bands, respectively, for γ = 1.8. The inferred comoving correlation lengths, also taking into account the bias by the source merging due to XMM-Newton PSF, are r c ≈ 9.8 ± 0.7, 5.8 -1.7 +1.4, and 12 ± 2 h -1 Mpc at the effective redshifts of z̄ eff ≈1.1, 0.9, and 0.6 for the SFT, MED, and UHD bands, respectively. If we include the integral constraint term in the fitting process, assuming that the power law extends to the scale length of the entire COSMOS XMM-Newton field, the correlation lengths become larger by ∼20%-90%. Comparing the inferred rms fluctuations of the spatial distribution of AGNs σ 8,AGN with those of the underlying mass, the bias parameters of the X-ray source clustering at these effective redshifts are in the range b AGN = 1.5-4.

AB - We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the ∼2 deg 2 COSMOS field (COSMOS XMM-Newton). Significant positive signals have been detected in the 0.5-2 (SFT) band, in the angle range of 0.5′-24′, while the positive signals were at the ∼2 and ∼3 σ levels in the 2-4.5 (MED) and 4.5-10 (UHD) keV bands, respectively. Correctly taking integral constraints into account is a major limitation in interpreting our results. With power-law fits to the ACFs without the integral constraint term, we find correlation lengths of θ c = 1.9″ ± 0.3″ , 0.8″ -0.4″ +0.5″ and 6″ ± 2″ for the SFT, MED, and UHD bands, respectively, for γ = 1.8. The inferred comoving correlation lengths, also taking into account the bias by the source merging due to XMM-Newton PSF, are r c ≈ 9.8 ± 0.7, 5.8 -1.7 +1.4, and 12 ± 2 h -1 Mpc at the effective redshifts of z̄ eff ≈1.1, 0.9, and 0.6 for the SFT, MED, and UHD bands, respectively. If we include the integral constraint term in the fitting process, assuming that the power law extends to the scale length of the entire COSMOS XMM-Newton field, the correlation lengths become larger by ∼20%-90%. Comparing the inferred rms fluctuations of the spatial distribution of AGNs σ 8,AGN with those of the underlying mass, the bias parameters of the X-ray source clustering at these effective redshifts are in the range b AGN = 1.5-4.

KW - Galaxies: active

KW - Quasars: general

KW - X-rays: galaxies

UR - http://www.scopus.com/inward/record.url?scp=35348893063&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=35348893063&partnerID=8YFLogxK

U2 - 10.1086/516579

DO - 10.1086/516579

M3 - Review article

AN - SCOPUS:35348893063

VL - 172

SP - 396

EP - 405

JO - Astrophysical Journal, Supplement Series

JF - Astrophysical Journal, Supplement Series

SN - 0067-0049

IS - 1

ER -