Clustering in Large Scale Galaxy Surveys: AGN
Yjan Gordon
University of Hull
Kevin Pimbblet (University of Hull, Monash University), Matt Owers (Macquarie University)
The widely accepted AGN unification model is not without its drawbacks. A major question to this is why not all type 2 AGN contain hidden broad line regions. One way of determining whether the unified model is a complete picture is to study the environment of AGN, which should be consistent for both type 1 and 2 if the viewing angle is the only difference between them. Although it is widely thought that mergers are an essential source of fuel for AGN, the timescale between merger and AGN activity remains unknown, and if a correlation is found between AGN type and environment it may suggest the evolutionary track of the AGN phase.
Looking at the clustering of AGN is an important method of studying environment, a method that is hindered by fibre collisions for large scale spectroscopic surveys that observe each field of view only once (e.g. SDSS). We show by means of a simple 2-point correlation function that the next generation of these surveys such as TAIPAN that repeatedly observe the same field of view and are therefore less inhibited by fibre collision, are inherently better at detecting clustering on the smallest angular scales. Thus they provide opportunity to study the environment of more interacting galaxies than possible with previous surveys.