Abstract Details
| Name: Kaustav Mitra Affiliation: Presidency University, Kolkata Conference ID: ASI2018_571 Title : Halo Occupation Distribution of Quasars : Revisiting the AGN Unification Authors and Co-Authors : Suchetana Chatterjee (Department of Physics, Presidency University), Michael A. DiPompeo (Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755, USA), Adam D. Myers (Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA) Zheng Zheng (Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA) Abstract Type : Poster Abstract Category : General Relativity and Cosmology Abstract : We model how active galaxies are distributed in the underlying large scale structure of the universe. We use a clustering statistic called the angular two-point correlation function (2PCF) of obscured and unobscured quasars : selected using the Wide-field Infrared Survey Explorer (WISE) and Sloan Digital Sky Survey (SDSS), at a median redshift of z ∼ 1. Our theoretical framework is five parameter Halo Occupation Distribution (HOD) model, derived from a cosmological hydrodynamic simulation by Chatterjee et al. (2012). The HOD parameterization was previously used to model the 2PCF of optically selected quasars and X-ray bright active galactic nuclei (AGN) at z ∼ 1. The current work shows that a single HOD parameterization can be used to model the population of different kinds of AGN in dark matter halos suggesting the universality in the relationship between AGN and their host dark matter halos. Our results show that the median halo mass of central quasar hosts increases from optically selected and infra-red (IR) bright unobscured populations to obscured quasars, signifying an increase in the degree of clustering. The projected satellite fractions also increase from optically bright to obscured quasars and tend to disfavor a simple orientation-only theory of AGN-unification. Our results also show that future measurements of the small scale clustering of obscured quasars can constrain current theories of AGN - supermassive black hole co-evolution where quasars evolve from an IR- bright obscured phase to the optically bright unobscured phase. Hence, from a cosmological large scale structure perspective we re-evaluate the Active galaxy unification schemes and hint towards prospective and exciting improvements of our understanding of galaxy evolution. |