Exploring Micro-Turbulence in Emission and Absorption in AGN

Heavily saturated UV absorption lines, such as those detected in BAL QSOs and a few Seyfert 1s, are typically quite broad. This can be due to superposition of many individual components, i.e., velocity gradients, or the domination of the profiles by the damped wings, i.e., a "walking wall" effect. Nevertheless, even the weakest UV absorption lines detected in Seyfert 1s have widths that are significantly greater than thermal. Interestingly, the smoothness of broad emission line profiles and underpredictions of the strengths of BLR lines and coronal NLR lines by photo-ionization models suggest the importance of micro-turbulence and associated dissipative heating within the emission-line gas. Hence, it is also possible that turbulence is important for the absorbers. We will discuss the evidence for turbulence and its possible role in the structure of gas in the proximity of an AGN.