Galaxy and Mass Assembly : the evolution of bias in the radio source population to z ∼ 1.5
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 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 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 , vol. 440 , no. 2 , pp. 1527-1541 . https://doi.org/10.1093/mnras/stu354
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
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