Abstract
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 produces the decorrelation between the
absorption lines and the continuum. A second study showed that the base
of the wind shields the broad emission-line region (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 spectral energy
distribution (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 Hubble Space Telescope 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 Kα
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 Kα line. Our results
highlight the importance of accounting for the effects of such winds in
the analysis of the physics of the central engine.
Original language | English |
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Article number | 141 |
Number of pages | 8 |
Journal | Astrophysical Journal |
Volume | 898 |
Issue number | 2 |
DOIs | |
Publication status | Accepted/In press - 12 Jun 2020 |
Keywords
- Galaxies: active
- Galaxies: individual (NGC 5548)
- Galaxies: nuclei
- Galaxies: Seyfert
- Line: formation