@article{ebf6e6b2558341dd9113871c8beab0ed,
title = "Galaxy interactions trigger rapid black hole growth: An unprecedented view from the Hyper Suprime-Cam survey",
abstract = "Collisions and interactions between gas-rich galaxies are thought to be pivotal stages in their formation and evolution, causing the rapid production of new stars, and possibly serving as amechanism for fueling supermassive black holes (BHs). Harnessing the exquisite spatial resolution (∼0.5) afforded by the first ∼170 deg2 of the Hyper Suprime- Cam (HSC) survey, we present our new constraints on the importance of galaxy-galaxy major mergers (1 : 4) in growing BHs throughout the last ∼8Gyr. Utilizing mid-infrared observations in the WISE all-sky survey, we robustly select active galactic nuclei (AGN) and mass-matched control galaxy samples, totaling ∼140000 spectroscopically confirmed systems at i < 22 mag. We identify galaxy interaction signatures using a novel machine-learning random forest decision tree technique allowing us to select statistically significant samples of major mergers, minor mergers / irregular systems, and noninteracting galaxies. We use these samples to show that galaxies undergoing mergers are a factor of ∼2-7 more likely to contain luminous obscured AGN than non-interacting galaxies, and this is independent of both stellarmass and redshift to z < 0.9. Furthermore, based on our comparison of AGN fractions in mass-matched samples, we determine that themost luminous AGN population (LAGN ≳ 1045 erg s-1) systematically reside in merging systems over non-interacting galaxies. Our findings show that galaxy-galaxy interactions do, on average, trigger luminous AGN activity substantially more often than in secularly evolving non-interacting galaxies, and we further suggest that the BH growth rate may be closely tied to the dynamical time of the merger system.",
keywords = "Active-galaxies, Evolution-galaxies, Galaxies, Interacting",
author = "Goulding, {Andy D.} and Greene, {Jenny E.} and Rachel Bezanson and Johnny Greco and Sean Johnson and Alexie Leauthaud and Yoshiki Matsuoka and Elinor Medezinski and Price-Whelan, {Adrian M.}",
note = "Funding Information: We thank the anonymous referee for their considered report, which allowed us to clarify and improve several aspects of this manuscript. ADG and JEG gratefully acknowledge support from the National Science Foundation under Grant Number AST-1613744. YM was supported by JSPS KAKENHI Grant No. JP17H04830. The authors thank Lisa Kewley, Robert Lupton, Jim Bosch, and Bob Armstrong for enlightening conversations. 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. The Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from the Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), the Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. Funding Information: We thank the anonymous referee for their considered report, which allowed us to clarify and improve several aspects of this manuscript. ADG and JEG gratefully acknowledge support from the National Science Foundation under Grant Number AST-1613744. YM was supported by JSPS KAKENHI Grant No. JP17H04830 Publisher Copyright: {\textcopyright} The Author(s) 2017. Published by Oxford University Press on behalf of the Astronomical Society of Japan. All rights reserved.",
year = "2018",
month = jan,
day = "1",
doi = "10.1093/pasj/psx135",
language = "English (US)",
volume = "70",
journal = "Publications of the Astronomical Society of Japan",
issn = "0004-6264",
publisher = "Astronomical Society of Japan",
number = "Special Issue 1",
}