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arXiv · 1402.5654

Galaxy and Mass Assembly (GAMA): The evolution of bias in the radio source population to z ~ 1.5

S. N. Lindsay·M. J. Jarvis·M. G. Santos·M. J. I. Brown·S. M. Croom·S. P. Driver·A. M. Hopkins·J. Liske·J. Loveday·P. Norberg·A. S. G. Robotham
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Abstract

We present a large-scale clustering analysis of radio galaxies in the Very Large Array (VLA) Faint Images of the Radio Sky at Twenty-cm (FIRST) survey over the Galaxy And Mass Assembly (GAMA) survey area, limited to S1.4 GHz >1 mJy with spectroscopic and photometric redshift limits up to r < 19.8 and r < 22 mag, respectively. For the GAMA spectroscopic matches, we present the redshift-space and projected correlation functions, the latter of which yielding a correlation length r0 ~ 8.2 Mpc/h and linear bias of ~1.9 at z ~ 0.34. Furthermore, we use the angular two-point correlation function w(θ) to determine spatial clustering properties at higher redshifts. We find r0 to increase from ~6 to ~14 Mpc/h between z = 0.3 and z = 1.55, with the corresponding bias increasing from ~2 to ~10 over the same range. Our results are consistent with the bias prescription implemented in the SKADS simulations at low redshift, but exceed these predictions at z > 1. This is indicative of an increasing (rather than fixed) halo mass and/or AGN fraction at higher redshifts or a larger typical halo mass for the more abundant FRI sources.

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S. N. Lindsay, M. J. Jarvis, M. G. Santos, M. J. I. Brown, S. M. Croom, S. P. Driver, A. M. Hopkins, J. Liske, J. Loveday, P. Norberg, A. S. G. Robotham. 2014-02-23. Galaxy and Mass Assembly (GAMA): The evolution of bias in the radio source population to z ~ 1.5. https://doi.org/10.1093/mnras%2Fstu354

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