Dependence of galaxy properties on void filament straightness

  • Shim, Junsup (Astronomy Program, Department of Physics and Astronomy, Seoul National University) ;
  • Lee, Jounghun (Astronomy Program, Department of Physics and Astronomy, Seoul National University) ;
  • Hoyle, Fiona (Pontifica Universidad Catolica de Ecuador)
  • Published : 2015.04.10

Abstract

We investigate the properties of galaxies belonging to the filaments in cosmic void regions, using the void catalogue constructed by Pan et al. (2012) from the SDSS DR7. To identify galaxy filaments within a void, voids with 30 or more galaxies are selected as a sample. We identify 3067 filaments in 1050 voids by applying the filament finding algorithm based on minimal spanning tree and reducing processes to spatial distribution of the void galaxies. We study the correlations between galaxy properties and the specific size of filament which quantifies the degree of the filament straightness. For example, the average magnitude and the magnitude of the faintest galaxy in filament decrease as the straightness of the filament increases. We also find that the correlations become stronger in rich filaments than in poor ones with fewer member galaxies. We discuss a physical explanation to our findings and their cosmological implications.

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