University of Oulu

Villarroel, B., Nyholm, A., Karlsson, T., Comerón, S., Korn, A., Sollerman, J., Zackrisson, E. (2017) AGN Luminosity and Stellar Age: Two Missing Ingredients for AGN Unification as Seen with iPTF Supernovae. Astrophysical Journal, 837 (2), 110. doi:10.3847/1538-4357/aa5d5a

AGN luminosity and stellar age : two missing ingredients for AGN unification as seen with iPTF supernovae

Saved in:
Author: Villarroel, Beatriz1,2; Nyholm, Anders3; Karlsson, Torgny1;
Organizations: 1Department of Physics and Astronomy, Uppsala University, SE-751 20, Uppsala, Sweden
2Centre for Interdisciplinary Mathematics ( CIM ) , Uppsala University, SE-751 06, Uppsala, Sweden
3Department of Astronomy and The Oskar Klein Centre, Stockholm University, SE-106 91 Stockholm, Sweden
4University of Oulu, Astronomy Research Unit, FI-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.7 MB)
Persistent link:
Language: English
Published: IOP Publishing, 2017
Publish Date: 2017-03-21


Active galactic nuclei (AGNs) are extremely powerful cosmic objects, driven by accretion of hot gas upon super-massive black holes. The zoo of AGN classes is divided into two major groups, with Type-1 AGNs displaying broad Balmer emission lines and Type-2 narrow ones. For a long time it was believed that a Type-2 AGN is a Type-1 AGN viewed through a dusty kiloparsec-sized torus, but an emerging body of observations suggests more than just the viewing angle matters. Here we report significant differences in supernova (SN) counts and classes in the first study to date of SNe near Type-1 and Type-2 AGN host galaxies, using data from the intermediate Palomar Transient Factory, the Sloan Digital Sky Survey Data Release 7, and Galaxy Zoo. We detect many more SNe in Type-2 AGN hosts (size of effect ~5.1σ) compared to Type-1 hosts, which shows that the two classes of AGN are located inside host galaxies with different properties. In addition, Type-1 and Type-2 AGNs that are dominated by star formation according to Wide-field Infrared Survey Explorer colors mW1mW2 < 0.5 and are matched in 22 μm absolute magnitude differ by a factor of ten in L[O III] λ5007 luminosity, suggesting that when residing in similar types of host galaxies Type-1 AGNs are much more luminous. Our results demonstrate two more factors that play an important role in completing the current picture: the age of stellar populations and the AGN luminosity. This has immediate consequences for understanding the many AGN classes and galaxy evolution.

see all

Series: Astrophysical journal
ISSN: 0004-637X
ISSN-E: 1538-4357
ISSN-L: 0004-637X
Volume: 837
Issue: 2
Article number: 110
DOI: 10.3847/1538-4357/aa5d5a
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: B.V. was funded and supported by the Center of Interdisciplinary Mathematics (Uppsala Universitet) and Erik and Märta Holmbergs donation from the Kungliga Fysiografiska Sällskapet. Supernova research at the Oskar Klein Centre is supported by the Swedish Research Council and by the Knut and Alice Wallenberg Foundation. The intermediate Palomar Transient Factory project is a scientific collaboration among the California Institute of Technology, Los Alamos National Laboratory, the University of Wisconsin, Milwaukee, the Oskar Klein Centre, the Weizmann Institute of Science, the TANGO Program of the University System of Taiwan, and the Kavli Institute for the Physics and Mathematics of the Universe. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research also heavily relies on the Sloan Digital Sky Survey (SDSS). Funding for SDSS-II has been provided by the Alfred P Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the Japanese Monbukagakusho, and the Max Planck Society.
Copyright information: © 2017. The American Astronomical Society. All rights reserved. Published in this repository with the kind permission of the publisher.