TY - JOUR
T1 - Infrared Spectral Energy Distribution and Variability of Active Galactic Nuclei
T2 - Clues to the Structure of Circumnuclear Material
AU - Lyu, Jianwei
AU - Rieke, George
N1 - Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/6
Y1 - 2022/6
N2 - The active galactic nucleus (AGN) phenomenon results from a supermassive black hole accreting its surrounding gaseous and dusty material. The infrared (IR) regime provides most of the information to characterize the dusty structures that bridge from the galaxy to the black hole, providing clues to the black hole growth and host galaxy evolution. Over the past several decades, with the commissioning of various ground, airborne and space IR observing facilities, our interpretations of the AGN circumnuclear structures have advanced significantly through an improved understanding of how their dust emission changes as a function of wavelength and how the heating of the dusty structures responds to variations in the energy released from the central engine. In this review, we summarize the current observational knowledge of the AGN IR broad-band spectral energy distributions (SEDs) and the IR time variability behavior covering large ranges of AGN luminosity and redshift, and discuss some first-order insights into the obscuring structures and host galaxy IR properties that can be obtained by integrating the relevant observations into a coherent picture.
AB - The active galactic nucleus (AGN) phenomenon results from a supermassive black hole accreting its surrounding gaseous and dusty material. The infrared (IR) regime provides most of the information to characterize the dusty structures that bridge from the galaxy to the black hole, providing clues to the black hole growth and host galaxy evolution. Over the past several decades, with the commissioning of various ground, airborne and space IR observing facilities, our interpretations of the AGN circumnuclear structures have advanced significantly through an improved understanding of how their dust emission changes as a function of wavelength and how the heating of the dusty structures responds to variations in the energy released from the central engine. In this review, we summarize the current observational knowledge of the AGN IR broad-band spectral energy distributions (SEDs) and the IR time variability behavior covering large ranges of AGN luminosity and redshift, and discuss some first-order insights into the obscuring structures and host galaxy IR properties that can be obtained by integrating the relevant observations into a coherent picture.
KW - AGN host galaxies
KW - IR astronomy
KW - IR galaxies
KW - Seyfert galaxies
KW - active galactic nuclei
KW - dust continuum emission
KW - quasars
KW - reverberation mapping
KW - spectral energy distribution
KW - time domain astronomy
UR - http://www.scopus.com/inward/record.url?scp=85131229585&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85131229585&partnerID=8YFLogxK
U2 - 10.3390/universe8060304
DO - 10.3390/universe8060304
M3 - Review article
AN - SCOPUS:85131229585
SN - 2218-1997
VL - 8
JO - Universe
JF - Universe
IS - 6
M1 - 304
ER -