The Atacama Cosmology Telescope: measuring radio galaxy bias through cross-correlation with lensing
Feb 23, 201510 pages
Published in:
- Mon.Not.Roy.Astron.Soc. 451 (2015) 1, 849-858
- Published: Jul 21, 2015
e-Print:
- 1502.06456 [astro-ph.CO]
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Abstract: (Oxford University Press)
We correlate the positions of radio galaxies in the FIRST survey with the cosmic microwave background lensing convergence estimated from the Atacama Cosmology Telescope over 470 deg^2 to determine the bias of these galaxies. We remove optically cross-matched sources below redshift z = 0.2 to preferentially select active galactic nuclei (AGN). We measure the angular cross-power spectrum at 4.4σ significance in the multipole range 100 < l < 3000, corresponding to physical scales within ≈2–60 Mpc at an effective redshift z_eff = 1.5. Modelling the AGN population with a redshift-dependent bias, the cross-spectrum is well fitted by the Planck best-fitting Λ cold dark matter cosmological model. Fixing the cosmology and assumed redshift distribution of sources, we fit for the overall bias model normalization, finding b(z_eff) = 3.5 ± 0.8 for the full galaxy sample and b(z_eff) = 4.0 ± 1.1(3.0 ± 1.1) for sources brighter (fainter) than 2.5 mJy. This measurement characterizes the typical halo mass of radio-loud AGN: we find .Note:
- 11 pages, 9 figures. Submitted to MNRAS
- large-scale structure of Universe
- radio continuum: galaxies
References(102)
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