A Direct Measurement of the Linear Bias of Mid-infrared-selected Quasars at z ≈ 1 Using Cosmic Microwave Background Lensing

• Published in: The Astrophysical Journal
• Main Authors: Geach, J. E., Lueker, M., Padin, S., Vieira, J. D.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Astronomical Society 2013
• Subjects: cosmology: observations; South pole
• Online Access: https://doi.org/10.1088/2041-8205/776/2/L41

We measure the cross-power spectrum of the projected mass density as traced by the convergence of the cosmic microwave background lensing field from the South Pole Telescope (SPT) and a sample of Type 1 and 2 (unobscured and obscured) quasars at 〈z〉 ~ 1 selected with the Wide-field Infrared Survey Explorer, over 2500 deg^2. The cross-power spectrum is detected at ≈7σ, and we measure a linear bias b = 1.61 ± 0.22, consistent with clustering analyses. Using an independent lensing map, derived from Planck observations, to measure the cross-spectrum, we find excellent agreement with the SPT analysis. The bias of the combined sample of Type 1 and 2 quasars determined in this work is similar to that previously determined for Type 1 quasars alone; we conclude that obscured and unobscured quasars trace the matter field in a similar way. This result has implications for our understanding of quasar unification and evolution schemes. © 2013 American Astronomical Society. Received 2013 July 3; accepted 2013 September 20; published 2013 October 7. SPT is supported by the NSF through grants ANT-0638937 and ANT-0130612. Support for this work is provided by: the NSF Physics Frontier Center grant PHY-0114422 to the Kavli Institute of Cosmological Physics at the University of Chicago; the Kavli Foundation and the Gordon and Betty Moore Foundation; NSF (grant numbers 1211096, 1211112 and PHYS-1066293); NASA through ADAP award NNX12AE38G; NSERC, CIfAR, and the Canada Research Chairs program. This research used resources of the National Energy Research Scientific Computing Center,which is supported by the Office of Science of the U.S. DoE under contract DE-AC02-05CH11231. Research at Argonne National Laboratory is supported by the Office of Science of the U.S. DoE under contract DE-AC02-06CH11357. Planck is an ESA science mission with instruments and contributions directly funded by ESA Member States, NASA, and Canada. Published - 2041-8205_776_2_L41.pdf Submitted - 1307.1706v2.pdf