Predictions of quasar clustering: Redshift, luminosity, and selection dependence

Robert J. Thacker, Evan Scannapieco, H. M P Couchman, Mark Richardson

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

We show that current clustering observations of quasars and luminous active galactic nuclei (AGNs) can be explained by a merger model augmented by feedback from outflows. Using numerical simulations large enough to study clustering out to 25 comoving h -1 Mpc, we calculate correlation functions, biases, and correlation lengths as a function of AGN redshift and optical and X-ray luminosity. At optical wavelengths, our results match a wide range of current observations and generate predictions for future data sets. We reproduce the weak luminosity dependence of clustering over the currently well-measured range and predict a much stronger dependence at higher luminosities. The increase in the amplitude of binary quasar clustering observed in the Sloan Digital Sky Survey (SDSS) is also reproduced and is predicted to occur at higher redshift, an effect that is due to the one-halo term in the correlation function. On the other hand, our results do not match the rapid evolution of the correlation length observed in the SDSS at z ≃ 3, a discrepancy that is at least partially due to differences in the scales probed by our simulation versus this survey. In fact, we show that changing the distances sampled from our simulations can produce changes as large as 40% in the fitted correlation lengths. Finally, in the X-ray, our simulations produce correlation lengths similar to that observed in the Chandra Deep Field (CDF) North, but not the significantly larger correlation length observed in the CDF-South.

Original languageEnglish (US)
Pages (from-to)552-563
Number of pages12
JournalAstrophysical Journal
Volume693
Issue number1
DOIs
StatePublished - Mar 1 2009

Fingerprint

quasars
luminosity
prediction
predictions
active galactic nuclei
simulation
merger
halos
x rays
outflow
wavelength
wavelengths

Keywords

  • galaxies: evolution
  • quasars: general

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Predictions of quasar clustering : Redshift, luminosity, and selection dependence. / Thacker, Robert J.; Scannapieco, Evan; Couchman, H. M P; Richardson, Mark.

In: Astrophysical Journal, Vol. 693, No. 1, 01.03.2009, p. 552-563.

Research output: Contribution to journalArticle

Thacker, Robert J. ; Scannapieco, Evan ; Couchman, H. M P ; Richardson, Mark. / Predictions of quasar clustering : Redshift, luminosity, and selection dependence. In: Astrophysical Journal. 2009 ; Vol. 693, No. 1. pp. 552-563.
@article{0ce55b8ae498404a93cc375c45e54b30,
title = "Predictions of quasar clustering: Redshift, luminosity, and selection dependence",
abstract = "We show that current clustering observations of quasars and luminous active galactic nuclei (AGNs) can be explained by a merger model augmented by feedback from outflows. Using numerical simulations large enough to study clustering out to 25 comoving h -1 Mpc, we calculate correlation functions, biases, and correlation lengths as a function of AGN redshift and optical and X-ray luminosity. At optical wavelengths, our results match a wide range of current observations and generate predictions for future data sets. We reproduce the weak luminosity dependence of clustering over the currently well-measured range and predict a much stronger dependence at higher luminosities. The increase in the amplitude of binary quasar clustering observed in the Sloan Digital Sky Survey (SDSS) is also reproduced and is predicted to occur at higher redshift, an effect that is due to the one-halo term in the correlation function. On the other hand, our results do not match the rapid evolution of the correlation length observed in the SDSS at z ≃ 3, a discrepancy that is at least partially due to differences in the scales probed by our simulation versus this survey. In fact, we show that changing the distances sampled from our simulations can produce changes as large as 40{\%} in the fitted correlation lengths. Finally, in the X-ray, our simulations produce correlation lengths similar to that observed in the Chandra Deep Field (CDF) North, but not the significantly larger correlation length observed in the CDF-South.",
keywords = "galaxies: evolution, quasars: general",
author = "Thacker, {Robert J.} and Evan Scannapieco and Couchman, {H. M P} and Mark Richardson",
year = "2009",
month = "3",
day = "1",
doi = "10.1088/0004-637X/693/1/552",
language = "English (US)",
volume = "693",
pages = "552--563",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Predictions of quasar clustering

T2 - Redshift, luminosity, and selection dependence

AU - Thacker, Robert J.

AU - Scannapieco, Evan

AU - Couchman, H. M P

AU - Richardson, Mark

PY - 2009/3/1

Y1 - 2009/3/1

N2 - We show that current clustering observations of quasars and luminous active galactic nuclei (AGNs) can be explained by a merger model augmented by feedback from outflows. Using numerical simulations large enough to study clustering out to 25 comoving h -1 Mpc, we calculate correlation functions, biases, and correlation lengths as a function of AGN redshift and optical and X-ray luminosity. At optical wavelengths, our results match a wide range of current observations and generate predictions for future data sets. We reproduce the weak luminosity dependence of clustering over the currently well-measured range and predict a much stronger dependence at higher luminosities. The increase in the amplitude of binary quasar clustering observed in the Sloan Digital Sky Survey (SDSS) is also reproduced and is predicted to occur at higher redshift, an effect that is due to the one-halo term in the correlation function. On the other hand, our results do not match the rapid evolution of the correlation length observed in the SDSS at z ≃ 3, a discrepancy that is at least partially due to differences in the scales probed by our simulation versus this survey. In fact, we show that changing the distances sampled from our simulations can produce changes as large as 40% in the fitted correlation lengths. Finally, in the X-ray, our simulations produce correlation lengths similar to that observed in the Chandra Deep Field (CDF) North, but not the significantly larger correlation length observed in the CDF-South.

AB - We show that current clustering observations of quasars and luminous active galactic nuclei (AGNs) can be explained by a merger model augmented by feedback from outflows. Using numerical simulations large enough to study clustering out to 25 comoving h -1 Mpc, we calculate correlation functions, biases, and correlation lengths as a function of AGN redshift and optical and X-ray luminosity. At optical wavelengths, our results match a wide range of current observations and generate predictions for future data sets. We reproduce the weak luminosity dependence of clustering over the currently well-measured range and predict a much stronger dependence at higher luminosities. The increase in the amplitude of binary quasar clustering observed in the Sloan Digital Sky Survey (SDSS) is also reproduced and is predicted to occur at higher redshift, an effect that is due to the one-halo term in the correlation function. On the other hand, our results do not match the rapid evolution of the correlation length observed in the SDSS at z ≃ 3, a discrepancy that is at least partially due to differences in the scales probed by our simulation versus this survey. In fact, we show that changing the distances sampled from our simulations can produce changes as large as 40% in the fitted correlation lengths. Finally, in the X-ray, our simulations produce correlation lengths similar to that observed in the Chandra Deep Field (CDF) North, but not the significantly larger correlation length observed in the CDF-South.

KW - galaxies: evolution

KW - quasars: general

UR - http://www.scopus.com/inward/record.url?scp=66549111146&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66549111146&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/693/1/552

DO - 10.1088/0004-637X/693/1/552

M3 - Article

AN - SCOPUS:66549111146

VL - 693

SP - 552

EP - 563

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -