The Two-Point Correlation of 2QZ Quasars and 2SLAQ LRGs: From a Quasar Fueling Perspective

Abstract

Public data from the 2dF quasar survey (2QZ) and 2dF/SDSS LRG & QSO (2SLAQ), with their vast reservoirs of spectroscopically located and identified sources, afford us the chance to more accurately study their real space correlations in the hopes of identifying the physical processes that trigger quasar activity. We have used these two public databases to measure the projected cross correlation, ${\omega }_p$, between quasars and luminous red galaxies. We find the projected two-point correlation to have a fitted clustering radius of $r_0,=5.3\pm 0.6$ and a slope, $\gamma =1.83\pm 0.42$ on scales from 0.7-27$h^{-1}$Mpc. We attempt to understand this strong correlation by separating the LRG sample into 2 populations of blue and red galaxies. We measure at the cross correlation with each population. We find that these quasars have a stronger correlation amplitude with the bluer, more recently starforming population in our sample than the redder passively evolving population, which has a correlation that is much more noisy and seems to flatten on scales $<5h^{-1}$Mpc. We compare this result to published work on hierarchical models. The stronger correlation of bright quasars with LRGs that have undergone a recent burst of starformation suggests that the physical mechanisms that produce both activities are related and that minor mergers or tidal effects may be important triggers of bright quasar activity and/or that bright quasars are less highly biased than faint quasars.

Accepted for publication in ApJ

References in corpus (13)

• The many lives of active galactic nuclei: cooling flows, black holes and the luminosities and colours of galaxies
• Energy input from quasars regulates the growth and activity of black holes and their host galaxies
• Black holes in galaxy mergers: The formation of red elliptical galaxies
• The 2dF-SDSS LRG and QSO Survey: QSO clustering and the L-z degeneracy
• Galaxy growth in the concordance $\Lambda$CDM cosmology
• The 2dF-SDSS LRG and QSO Survey: The LRG 2-Point Correlation Function and Redshift-Space Distortions
• The 2dF-SDSS LRG and QSO (2SLAQ) Luminous Red Galaxy Survey
• The 2dF-SDSS LRG and QSO survey: Evolution of the Luminosity Function of Luminous Red Galaxies to z=0.6
• The clustering of narrow-line AGN in the local Universe
• The 2dF-SDSS LRG and QSO survey: evolution of the clustering of luminous red galaxies since z = 0.6
• The Small-Scale Environment of Quasars
• On Statistical Lensing and the Anti-Correlation Between 2dF QSOs and Foreground Galaxies
• The 2dF-SDSS LRG and QSO Survey: The Star Formation Histories of Luminous Red Galaxies

Cited by in corpus (2)

• Quasar-Galaxy Clustering through Projected Galaxy Counts at z=0.6-1.2
• Early Science Result from the Japanese Virtual Observatory: AGN and Galaxy Clustering at z = 0.3 to 3.0