The Low-Redshift Quasar-Quasar Correlation Function from an Extragalactic Halpha Emission-Line Survey to z=0.4

• Published in: arXiv.org 2000-12
• Main Authors: Sabbey, C N, Oemler, A, Coppi, P, Baltay, C, Bongiovanni, A, Bruzual, G, Garcia, C E, Musser, J, Rengstorf, A W, Snyder, J A
• Format: Article
• Language: English
• Subjects: Active galactic nuclei; Amplitudes; Clustering; Computer simulation; Confidence intervals; Emission analysis; Galaxies; Galaxy distribution; Quasars; Red shift; Seyfert galaxies; Spatial distribution; Spectroscopy; Spectrum analysis
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.9912108

We study the large-scale spatial distribution of low-redshift quasars and Seyfert~1 galaxies using a sample of 106 luminous emission-line objects (\(\bar{M}_{B} \approx -23\)) selected by their H\(\alpha\) emission lines in a far-red objective prism survey (\(0.2 < z < 0.37\)). Of the 106 objects, 25 were previously known AGN (Veron-Cetty and Veron 2000), and follow-up spectroscopy for an additional 53 objects (including all object pairs with separation \(r < 20 \hmpc\)) confirmed 48 AGN and 5 narrow emission-line galaxies (NELGs). The calculated amplitude of the spatial two-point correlation function for the emission-line sample is \(A = 0.4 \cdot \bar{\xi}(r < 20 \hmpc) \cdot 20^{1.8} = 142 \pm 53\). Eliminating the confirmed NELGs from the sample we obtain the AGN clustering amplitude \(A = 98 \pm 54\). Using Monte Carlo simulations we reject the hypothesis that the observed pair counts were drawn from a random distribution at the 99.97% and 98.6% confidence levels for the entire sample and the AGN subset respectively. We measure a decrease in the quasar clustering amplitude by a factor of \(3.7 \pm 2.0\) between \(z = 0.26\) and \(z \approx 1.5\), and present the coordinates, redshifts, and follow-up spectroscopy for the 15 previously unknown AGN and 4 luminous NELGs that contribute to the clustering signal.