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We investigate the relationship between the long term X-ray spectralvariability in the Seyfert 1.5 galaxy NGC 4151 and its intrinsic absorption, bycomparing the 2014 simultaneous ultraviolet/X-Ray observations taken withHubble STIS Echelle and Chandra HETGS with archival observations from Chandra,XMM-Newton and Suzaku. The observations are divided into "high" and "low"states, with the low states showing strong and unabsorbed extended emission atenergies below 2 keV. Our X-ray model consists of a broken powerlaw, neutralreflection and the two dominant absorption components identified by Kraemer etal. (2005), hereafter KRA2005, X-High and D+Ea, which are present in allepochs. The model fittings suggest that the absorbers are very stable, with theprincipal changes in the intrinsic absorption resulting from variations in theionization state of the gas as the ionizing continuum varies. However, the lowstates show evidence of larger column densities in one or both of theabsorbers. Among plausible explanations for the column increase, we discuss thepossibility of an expanding/contracting X-ray corona. As suggested by KRA2005,there seem to be contributions from magnetohydrodynamic (MHD) winds to the massoutflow. Along with the ultra fast outflow absorber identified by Tombesi etal. (2010), X-High is consistent with being magnetically driven. On the otherhand, it is unlikely that D+Ea is part of the MHD flow, and it is possible thatit is radiatively accelerated. These results suggest that at a sufficientlylarge radial distance there is a break point between MHD-dominated andradiatively driven outflows.

New Insights in the Spectral Variability and Physical Conditions of the X-ray Absorbers in NGC 4151