The host galaxies and classification of active galactic nuclei

We present an analysis of the host properties of 85 224 emission-line galaxies selected from the Sloan Digital Sky Survey. We show that Seyferts and low-ionization narrow emission-line regions (LINERs) form clearly separated branches on the standard optical diagnostic diagrams. We derive a new empirical classification scheme which cleanly separates star-forming galaxies, composite active galactic nucleus-H II (AGN-H II) galaxies, Seyferts and LINERs and we study the host galaxy properties of these different classes of objects. LINERs are older, more massive, less dusty, less concentrated, and they have higher velocity dispersions and lower [O III] luminosities than Seyfert galaxies have. Seyferts and LINERs…

• NS
  National Science Foundation
• UD
  U.S. Department of Energy
• NA
  National Aeronautics and Space Administration
• AP
  Alfred P. Sloan Foundation
• PU
  Princeton University
• UO
  University of Chicago
• UO
  University of Washington
• JH
  Johns Hopkins University
• UO
  University of Pittsburgh
• NM
  New Mexico State University
• M
  Max-Planck-Gesellschaft
• MF
  Max-Planck-Institut für Astronomie
• UN
  U.S. Naval Observatory
• F
  Fermilab
• LA
  Los Alamos National Laboratory