Space Telescope and Optical Reverberation Mapping Project. XI. Disk-wind Characteristics and Contributions to the Very Broad Emission Lines of NGC 5548
Version 2 2021-01-19, 09:00Version 2 2021-01-19, 09:00
Version 1 2020-07-03, 16:54Version 1 2020-07-03, 16:54
journal contribution
posted on 2021-01-19, 09:00authored byM Dehghanian, GJ Ferland, GA Kriss, BM Peterson, KT Korista, MR Goad, M Chatzikos, F Guzman, G de Rosa, M Mehdipour, J Kaastra, S Mathur, M Vestergaard, D Proga, T Waters, MC Bentz, S Bisogni, WN Brandt, E Dalla Bont a, MM Fausnaugh, JM Gelbord, Keith Horne, IM McHardy, RW Pogge, DA Starkey
In 2014 the NGC 5548 Space Telescope and Optical Reverberation Mapping
campaign discovered a two-month anomaly when variations in the absorption and
emission lines decorrelated from continuum variations. During this time the
soft X-ray part of the intrinsic spectrum had been strongly absorbed by a
line-of-sight (LOS) obscurer, which was interpreted as the upper part of a disk
wind. Our first paper showed that changes in the LOS obscurer produce the
decorrelation between the absorption lines and the continuum. A second study
showed that the base of the wind shields the BLR, leading to the emission-line
decorrelation. In that study, we proposed the wind is normally transparent with
no effect on the spectrum. Changes in the wind properties alter its shielding
and affect the SED striking the BLR, producing the observed decorrelations. In
this work, we investigate the impact of a translucent wind on the emission
lines. We simulate the obscuration using XMM-Newton, NuSTAR, and HST
observations to determine the physical characteristics of the wind. We find
that a translucent wind can contribute a part of the He II and Fe K? emission.
It has a modest optical depth to electron scattering, which explains the
fainter far-side emission in the observed velocity delay maps. The wind
produces the very broad base seen in the UV emission lines and may also be
present in the Fe K? line. Our results highlight the importance of accounting
for the effects of such winds in the analysis of the physics of the central
engine.
History
Citation
2020 ApJ 898 141
Author affiliation
Department of Physics and Astronomy
Version
VoR (Version of Record)
Published in
Astrophysical Journal
Volume
898
Issue
2
Publisher
Institute of Physics (IOP) for American Astronomical Society