X-ray and Ultraviolet Absorbing Outflows In Quasars

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Session 17 -- Radio Galaxies and High Luminosity AGNs
Oral presentation, Monday, 30, 1994, 10:00-11:30

[17.06] X-ray and Ultraviolet Absorbing Outflows In Quasars

S. Mathur, B. Wilkes, M. Elvis and F. Fiore (SAO)

\def\etal {et~al. } \def\lax {${_<\atop^{\sim}}$} \def\gax {${_>\atop^{\sim}}$}

We will present new results on absorbing outflows in quasars 3C351 (Mathur \etal~ 1994) and 3C212 (Mathur 1994). We have shown that the X-ray and UV absorption observed in these quasars' spectra is due to the same material. This new discovery enables us to constrain the physical characteristics of the absorbing material through the combined X-ray and UV analysis. In 3C351 the absorber is found to be outflowing (v $\sim 2000 km~s^{-1}$), highly ionized (U = 6--12), has large column density ($N_H =$ 1 -- 2 $\times 10^{22} cm^{-2}$), is situated outside the broad emission line region (R $> 1/3 ~pc.$), and has low density (n \lax $10^7 cm^{-3}$). The corresponding mass loss rate is $0.05<$ \.{M} $< 5 ~M_{\odot} ~yr^{-1}$ for covering factors between 1\% and unity. The radiation pressure experienced by the ionized absorber is easily sufficient to accelerate it to outflow velocities of a few thousand km s$^{-1}$. These properties describe a component of nuclear material not previously recognized.

In 3C212 the absorber is again required to be partially ionized and the low energy X-ray absorption is caused by residual metal opacity. Normally X-ray absorbers are assumed to be neutral unless a recovery of the X-ray spectrum is seen at low energies. The identification of the X-ray absorber with the UV absorber in 3C212 demonstrates a new method to identify ionized X-ray absorbers even when the X-ray data itself is inadequate.

We now suspect that many more cases of ionized absorbers will be identified in this way and that the large number of derivable physical parameters will allow us to understand the origin of this material and its role in active galactic nuclei.

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