|Title:||The Void Galaxy Survey: A filamentary structure in the void|
|Date:||Thursday, 16 October 2014|
|Time:||11:00 - 12:00|
Cosmic voids are vast regions occupying most of the volume in the universe with sizes in the range of 20 – 60 h-1 Mpc, usually roundish in shape and largely devoid of galaxies . In the large scale structure of the universe we observe today, the most striking features along with the voids are clusters and filaments. In this picture, galaxies are distributed in a filament-dominated web-like structure. Filaments connect clusters to each other and, while tenuous, act like bridges. The very low density of the void regions, we do find a dilute population of galaxies in their interior. Void galaxies may be the rare probes of the faint and tenuous substructure that hierarchical structure formation theories predict to exist in voids. Cosmological simulations show how voids are filled by low-density dark matter filaments, creating a network of tenuous substructures within their interior. This may indicate that the galaxies residing in voids are formed along these dark matter filaments, given that the simulations reveal that dark matter halos are forming along them.
In my talk, I will describe the Void Galaxy Survey (VGS) which is a multiwavelength survey of 60 void galaxies. Our sample is a unique in its way of being selected geometrically therefore is not biased to color, morphology and any other physical properties. I will first present our sample and the VGS. I will talk about the gas content, structural parameters and star formation properties of the VGS galaxies. Then I will present a special case we have in our sample which is a candidate of a filamentary structure in a void. I will talk about the what we learn about this system from observation and simulation.