Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2011-02-23
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
18 emulateapj pages, 14 figures, 1 table; accepted for publication in ApJ
Scientific paper
We present the first measurement of the spatial clustering of mid-infrared selected obscured and unobscured quasars, using a sample in the redshift range 0.7 < z < 1.8 selected from the 9 deg^2 Bootes multiwavelength survey. Recently the Spitzer Space Telescope and X-ray observations have revealed large populations of obscured quasars that have been inferred from models of the X-ray background and supermassive black hole evolution. To date, little is known about obscured quasar clustering, which allows us to measure the masses of their host dark matter halos and explore their role in the cosmic evolution of black holes and galaxies. In this study we use a sample of 806 mid-infrared selected quasars and ~250,000 galaxies to calculate the projected quasar-galaxy cross-correlation function w_p(R). The observed clustering yields characteristic dark matter halo masses of log (M_halo [h^-1 M_sun]) = 12.7^+0.4_-0.6 and 13.3^+0.3_-0.4 for unobscured quasars (QSO-1s) and obscured quasars (Obs-QSOs), respectively. The results for QSO-1s are in excellent agreement with previous measurements for optically-selected quasars, while we conclude that the Obs-QSOs are at least as strongly clustered as the QSO-1s. We test for the effects of photometric redshift errors on the optically-faint Obs-QSOs, and find that our method yields a robust lower limit on the clustering; photo-z errors may cause us to underestimate the clustering amplitude of the Obs-QSOs by at most ~20%. We compare our results to previous studies, and speculate on physical implications of stronger clustering for obscured quasars.
Alexander David M.
Assef Roberto J.
Brodwin Mark
Brown Michael J. I.
Caldwell Nelson
No associations
LandOfFree
Clustering of obscured and unobscured quasars in the Bootes field: Placing rapidly growing black holes in the cosmic web does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Clustering of obscured and unobscured quasars in the Bootes field: Placing rapidly growing black holes in the cosmic web, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clustering of obscured and unobscured quasars in the Bootes field: Placing rapidly growing black holes in the cosmic web will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-85787