Galaxy and Mass Assembly: the evolution of bias in the radio source population to z∼1.5

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

Abstract

We present a large-scale clustering analysis of radio galaxies in the Very Large Array Faint Images of the Radio Sky at Twenty-cm 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 <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 h−1 Mpc 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 h−1 Mpc between z = 0.3 and 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 SKA Design Study simulations at low redshift, but exceed these predictions at z > 1. This is indicative of an increasing (rather than fixed) halo mass and/or active galactic nuclei fraction at higher redshifts or a larger typical halo mass for the more abundant Fanaroff and Riley Class I sources.

Citation

Lindsay, S., Jarvis, M., Santos, M., Brown, M., Croom, S., Driver, S., …Robotham, A. (2014). Galaxy and Mass Assembly: the evolution of bias in the radio source population to z∼1.5. Monthly Notices of the Royal Astronomical Society, 440(2), 1527-1541. https://doi.org/10.1093/mnras/stu354

• Journal Article Type: Article
• Publication Date: May 1, 2014
• Deposit Date: Jun 3, 2014
• Publicly Available Date: Jul 3, 2014
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 440
• Issue: 2
• Pages: 1527-1541
• DOI: https://doi.org/10.1093/mnras/stu354
• Keywords: Surveys, Galaxies: active, Large-scale structure of Universe, Radio continuum: galaxies.
• Public URL: https://durham-repository.worktribe.com/output/1451647