http://arxiv.org/abs/1611.00512
The gravitationally lensed quasar APM 08279+5255 has the fastest claimed AGN wind, with velocities of 0.6–0.7c. This would require magnetic driving mechanism since this exceeds the radiation drag limit for any radiation driving. This conclusion derives from interpreting both the narrow and broad absorption features in the X-ray spectrum as iron absorption lines. However, the classic ultrafast outflow source PDS 456 also shows similar absorption systems, but here the higher energy, broader feature is generally interpreted as a more complex absorption edge. We reanalyse all the spectra from APM 08279+5255 using a full 3-dimensional Monte Carlo radiative transfer disc wind model for the ionised wind at 0.1–0.2c, together with complex absorption from lower ionisation material, and find that this is a better description of the data. Thus there is no strong requirement for outflow velocities beyond 0.2c, which can be powered by radiation driving. We show that UV line driving is especially likely given the spectral energy distribution of this source which is intrinsically UV bright and X-ray weak. While the peak of this emission is unobservable, it must be luminous enough to power the observed hot dust. This favours at least moderate black hole spins. We show that both the X-ray and broad UV absorption lines show a correlated decrease in equivalent width over 6 years. The observed flux does not vary, indicating that the changing X-ray wind affects the continuum seen by the UV outflow, or that both respond to a change in the unseen far UV flux.
K. Hagino, C. Done, H. Odaka, et. al.
Thu, 3 Nov 16
33/57
Comments: 12 pages, 8 figures, submitted to MNRAS
You must be logged in to post a comment.