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

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

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6 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)3435-3450
Number of pages16
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
Publication statusPublished - 1 Mar 2018


  • Galaxies: kinematics and dynamics
  • Galaxies: statistics

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