The First Swift Intensive AGN Accretion Disk Reverberation Mapping Survey
Peterson, B. M.
Barth, A. J.
Starkey, D. A.
Bentz, Misty C.
Brandt, W. N.
Breeveld, A. A.
Cenko, S. B.
AffiliationUniv Arizona, Steward Observ
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationR. Edelson et al 2019 ApJ 870 123
Rights© 2019. The American Astronomical Society. All rights reserved.
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AbstractSwift intensive accretion disk reverberation mapping of four AGN yielded light curves sampled similar to 200-350 times in 0.3-10 keV X-ray and six UV/optical bands. Uniform reduction and cross-correlation analysis of these data sets yields three main results: (1) The X-ray/UV correlations are much weaker than those within the UV/optical, posing severe problems for the lamp-post reprocessing model in which variations in a central X-ray corona drive and power those in the surrounding accretion disk. (2) The UV/optical interband lags are generally consistent with tau proportional to lambda(4/3) as predicted by the centrally illuminated thin accretion disk model. While the average interband lags are somewhat larger than predicted, these results alone are not inconsistent with the thin disk model given the large systematic uncertainties involved. (3) The one exception is the U band lags, which are on average a factor of similar to 2.2 larger than predicted from the surrounding band data and fits. This excess appears to be due to diffuse continuum emission from the broad-line region (BLR). The precise mixing of disk and BLR components cannot be determined from these data alone. The lags in different AGN appear to scale with mass or luminosity. We also find that there are systematic differences between the uncertainties derived by JAVELIN versus more standard lag measurement techniques, with JAVELIN reporting smaller uncertainties by a factor of 2.5 on average. In order to be conservative only standard techniques were used in the analyses reported herein.
VersionFinal published version
SponsorsNASA under the ADAP award [80NSSC17K0126]; NSF [AST-1412693]; STFC [ST/R000824/1]; UK Space Agency; National Science Foundation through CAREER grant [AST-1253702]; Science and Technology Facilities Council (STFC) [ST/P000541/1]; Independent Research Fund Denmark [DFF 4002-00275]; NWO, the Netherlands Organization for Scientific Research