Guo, Quan and Cole, Shaun and Eke, Vincent and Frenk, Carlos and Helly, John (2013) 'Spatial and luminosity distributions of galactic satellites.', Monthly notices of the Royal Astronomical Society., 434 (3). pp. 1838-1848.
We investigate the luminosity functions and projected number density profiles of galactic satellites around isolated primaries of different luminosity. We measure these quantities for model satellites placed into the Millennium and Millennium II dark matter simulations by the GALFORM semi-analytic galaxy formation model for different bins of primary galaxy magnitude and we investigate their dependence on satellite luminosity. We compare our model predictions to the data of Guo et al. from the Sloan Digital Sky Survey Data Release 8 (SDSS DR8). First, we use a mock light-cone catalogue to verify that the method we used to count satellites in the SDSS DR8 is unbiased. We find that the radial distributions of model satellites can be fitted by a Navarro–Frenk–White profile similar to those around comparable primary galaxies in the SDSS DR8, with only slight differences at low luminosities and small projected radii. However, when splitting the satellites by colour, the model and SDSS satellite systems no longer resemble one another, with many red model satellites in contrast to the dominant blue fraction at similar luminosity in the SDSS. The few model blue satellites are also significantly less centrally concentrated in the halo of their stacked primary than their SDSS counterparts. We discuss how these discrepancies may reflect inadequacies in the treatment of the processes that determine the star formation histories of small galaxies in the model.
|Keywords:||Galaxies, Dwarf galaxies, Fundamental parameters, Local group, Statistics, Structure.|
|Full text:||(VoR) Version of Record|
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|Publisher Web site:||http://dx.doi.org/10.1093/mnras/stt903|
|Publisher statement:||This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.|
|Date accepted:||No date available|
|Date deposited:||22 May 2014|
|Date of first online publication:||September 2013|
|Date first made open access:||No date available|
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