Evidence for an Outer Component in the Continuum Reverberation Mapping of Active Galactic Nuclei
Abstract Continuum reverberation mapping is widely used in studying the accretion disks of active galactic nuclei (AGNs). Some indirect evidence and simulations have indicated that the diffuse continuum, especially the strong Balmer continuum from the broad-line region, may contribute to the continu...
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Published in | The Astrophysical journal Vol. 966; no. 2; pp. 149 - 162 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Philadelphia
The American Astronomical Society
01.05.2024
IOP Publishing |
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
Continuum reverberation mapping is widely used in studying the accretion disks of active galactic nuclei (AGNs). Some indirect evidence and simulations have indicated that the diffuse continuum, especially the strong Balmer continuum from the broad-line region, may contribute to the continuum in the
u
/
U
band. Here, we present direct evidence for this contribution. In this work, we apply the ICCF-Cut method to continuum reverberation mapping to extract the possible diffuse continuum light curves of six AGNs, using high-cadence, high-quality, and multiband observations. We find the existence of an outer component out of the accretion disk for each of the six AGNs in the Swift
U
band. Meanwhile, similar results can be derived with the JAVELIN Photometric Reverberation Mapping Model for four of them. The lags of the outer components are consistent with the predicted Balmer continuum lags, which are about half of the H
β
lag values. Our result directly reinforces the understanding that an outer component, especially the Balmer continuum in the rest-frame
u
/
U
band, can contribute significantly to the continuum reverberation lags of AGNs. |
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Bibliography: | Galaxies and Cosmology AAS51434 |
ISSN: | 0004-637X 1538-4357 |
DOI: | 10.3847/1538-4357/ad36c0 |