For the past decade , ionized outflows of a few 100 km s ^ { -1 } from nearby Seyfert galaxies have been studied in great detail using high resolution X-ray absorption spectra .
A recurring feature of these outflows is their broad ionization distribution including essentially ions ( e.g. , of Fe ) from neutral to fully ionized .
The absorption measure distribution ( AMD ) is defined as the distribution of column density with ionization parameter \left|dN _ { H } / d ( \log \xi ) \right| . AMD s of Seyfert outflows can span up to five orders of magnitude in \xi .
We present the AMD of five outflows and show that they are all rather flat , perhaps slightly rising towards high ionization .
More quantitatively , a power-law fit for \log AMD \propto ( \log \xi ) ^ { a } yields slopes of 0 < a < 0.4 .
These slopes tightly constrain the density profiles of the wind , which until now could be addressed only by theory .
If the wind is distributed on large scales , the measured slopes imply a generic density radial profile of n \propto r ^ { - \alpha } with 1 < \alpha < 1.3 .
This scaling rules out a mass conserving radial flow of n \propto r ^ { -2 } , or a constant density absorber , but is consistent with a non-spherical MHD outflow model in which n \propto r ^ { -1 } along any given line of sight .
On the other hand , if ionization variations are a result of local ( \delta r ) density gradients , e.g .
as in the turbulent interstellar medium ( ISM ) , the AMD slopes imply density scaling of n \propto \delta r ^ { - \alpha } with 0.7 < \alpha < 1.0 , which is quite different from the scaling of approximately n \propto \delta r ^ { 0.4 } found in the Milky Way ISM and typical of incompressible turbulence .