The Warped Disc of NGC 4258

Abstract

We consider the properties of the warped accretion disc in NGC 4258 which is delineated by maser emission. We use our analytical models to consider whether the disc could be warped by Lense-Thirring precession. We show that such models fit the shape of the disc well and we determine the goodness of fit for various combinations of the warp radius and the disc and black hole configurations. Though the fits are compelling evidence, we note that such a model has implications for the formation and longevity of the disc which might be problematic for the current understanding of Seyfert Galaxies.