The soft X-ray cluster-AGN spatial cross-correlation function in the ROSAT-NEP survey

Nico Cappelluti, H. Böhringer, P. Schuecker, E. Pierpaoli, C. R. Mullis, I. M. Gioia, J. P. Henry

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Context. X-ray surveys facilitate investigations of the environment of AGNs. Deep Chandra observations have revealed that the AGN source surface density rises near clusters of galaxies. The natural extension of this finding is the measurement of spatial clustering of AGNs around clusters and the investigation of relative biasing between active galactic nuclei and galaxies near clusters. Aims. We aim to measure the correlation length of AGNs around clusters and the average clustering properties of a complete sample of AGNs in a dense environment. Methods. We present the first measurement of the soft X-ray cluster-AGN cross-correlation function in redshift space using the data of the ROSAT-NEP survey. The survey covers 9×9 deg2 around the North Ecliptic Pole where 442 X-ray sources were detected and almost completely spectroscopically identified. Results. We detected a >3σ significant clustering signal on scales s ≤ 50 h70-1 Mpc. We performed a classical maximum-likelihood power-law fit to the data and obtained a correlation length s0 = 8.70.3+1.2 h 70-1 Mpc and a slope γ = 1.70.7 +0.2, (1σ errors). Conclusions. This is strong evidence that AGNs are good tracers of the large scale structure of the Universe. Our data were compared to the results obtained by cross-correlating X-ray clusters and galaxies. We observe, with a large uncertainty, a similar behaviour of AGN clustering around clusters similar to the clustering of galaxies around clusters.

Original languageEnglish (US)
Pages (from-to)35-40
Number of pages6
JournalAstronomy and Astrophysics
Volume465
Issue number1
DOIs
StatePublished - Apr 1 2007
Externally publishedYes

Fingerprint

cross correlation
x rays
galaxies
power law
tracer
large-scale structure of the universe
ecliptic
active galactic nuclei
tracers
poles
slopes

Keywords

  • Cosmology: dark matter
  • Cosmology: large-scale structure of universe
  • Galaxies: active
  • Galaxies: clusters: general
  • X-rays: galaxies: clusters

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Cappelluti, N., Böhringer, H., Schuecker, P., Pierpaoli, E., Mullis, C. R., Gioia, I. M., & Henry, J. P. (2007). The soft X-ray cluster-AGN spatial cross-correlation function in the ROSAT-NEP survey. Astronomy and Astrophysics, 465(1), 35-40. https://doi.org/10.1051/0004-6361:20065920

The soft X-ray cluster-AGN spatial cross-correlation function in the ROSAT-NEP survey. / Cappelluti, Nico; Böhringer, H.; Schuecker, P.; Pierpaoli, E.; Mullis, C. R.; Gioia, I. M.; Henry, J. P.

In: Astronomy and Astrophysics, Vol. 465, No. 1, 01.04.2007, p. 35-40.

Research output: Contribution to journalArticle

Cappelluti, N, Böhringer, H, Schuecker, P, Pierpaoli, E, Mullis, CR, Gioia, IM & Henry, JP 2007, 'The soft X-ray cluster-AGN spatial cross-correlation function in the ROSAT-NEP survey', Astronomy and Astrophysics, vol. 465, no. 1, pp. 35-40. https://doi.org/10.1051/0004-6361:20065920
Cappelluti, Nico ; Böhringer, H. ; Schuecker, P. ; Pierpaoli, E. ; Mullis, C. R. ; Gioia, I. M. ; Henry, J. P. / The soft X-ray cluster-AGN spatial cross-correlation function in the ROSAT-NEP survey. In: Astronomy and Astrophysics. 2007 ; Vol. 465, No. 1. pp. 35-40.
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