Galaxy and Mass Assembly (GAMA): small-scale anisotropic galaxy clustering and the pairwise velocity dispersion of galaxies

Loveday, J.; Christodoulou, L.; Norberg, P.; Peacock, J.A.; Baldry, I.K.; Bland-Hawthorn, J.; Brown, M.J.I.; Colless, M.; Driver, S.P.; Holwerda, B.W.; Hopkins, A.M.; Kafle, P.R.; Liske, J.; Lopez-Sanchez, A.R.; Taylor, E.N.

Abstract

The galaxy pairwise velocity dispersion (PVD) can provide important tests of non-standard gravity and galaxy formation models. We describe measurements of the PVD of galaxies in the Galaxy and Mass Assembly (GAMA) survey as a function of projected separation and galaxy luminosity. Due to the faint magnitude limit (r < 19.8) and highly complete spectroscopic sampling of the GAMA survey, we are able to reliably measure the PVD to smaller scales (r⊥ = 0.01 h − 1 Mpc) than previous work. The measured PVD at projected separations r⊥ ≲ 1 h − 1 Mpc increases near monotonically with increasing luminosity from σ12 ≈ 200 km s − 1 at Mr = −17 mag to σ12 ≈ 600 km s − 1 at Mr ≈ −22 mag. Analysis of the Gonzalez-Perez et al. (2014) GALFORM semi-analytic model yields no such trend of PVD with luminosity: the model overpredicts the PVD for faint galaxies. This is most likely a result of the model placing too many low-luminosity galaxies in massive haloes.

Citation

Loveday, J., Christodoulou, L., Norberg, P., Peacock, J., Baldry, I., Bland-Hawthorn, J., …Taylor, E. (2018). Galaxy and Mass Assembly (GAMA): small-scale anisotropic galaxy clustering and the pairwise velocity dispersion of galaxies. Monthly Notices of the Royal Astronomical Society, 474(3), 3435-3450. https://doi.org/10.1093/mnras/stx2971

• Journal Article Type: Article
• Acceptance Date: Nov 13, 2017
• Online Publication Date: Nov 17, 2017
• Publication Date: Mar 1, 2018
• Deposit Date: Jan 15, 2018
• Publicly Available Date: Jan 16, 2018
• 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: 474
• Issue: 3
• Pages: 3435-3450
• DOI: https://doi.org/10.1093/mnras/stx2971
• Public URL: https://durham-repository.worktribe.com/output/1336726