A New Perspective on the AGN History: The First Unbiased Measure of AGN Clustering in the Local Universe in the Hard X-ray Swift-BAT All Sky Survey
Abstract
We present the first measurement of AGN clustering in the local Universe obtained with the 100% spectroscopically complete sample of the Swift all-sky survey. This provides, for the first time, a view of AGN clustering which is not biased by dust absorption. Since our energy band is not sensitive to photoelectric absorption. Our measurements include the contribution of highly absorbed, even Compton Thick, AGN which have always been neglected in this kind of study. The study of clustering in the local universe <z>=0.02 is fundamental for testing current models of AGN formation which are based on galaxy merging. We have computed for the first time the 3D autocorrelation function of AGN with 14-200 keV luminosity 42 <log(L) < 45. We also provide an estimated of the autocorrelation function for absorbed and unabsorbed sources and in luminosity classed. It is commonly assumed that AGN are triggered by mergers and such a paradigm has been tested several times through simulations and observation. Our measures provide a clear picture of the final products of the so called "merger trees", and provide an additional, valuable, ingredient for understanding how AGN grow form and evolve.
- Publication:
-
AAS/High Energy Astrophysics Division #11
- Pub Date:
- March 2010
- Bibcode:
- 2010HEAD...11.3504N