On the origin of X-ray dips in Her X-1

A strong X-ray illumination of the optical star atmosphere in Her X-l, asym metric because of a partial shadowing by the tilted twisted accretion disk around central neutron star, leads to the formation of matter flows coming out of the orbital plane and crossing the line of sight before entering the disk. We suggest that the absorption of X-ray emission by this flow leads to the formation of pre-eclipse and anomalous dips of type I. These dips ar e observed during several orbits after turn-on both in the main-on and shor t-on state. Almost coherent action of tidal torques and matter streams enha nces the disk wobbling which causes the disk edge to shield the X-ray sourc e after the turn-on. Anomalous dips of type II and post-eclipse recovery ap pear due to this process only on the first orbit after turn-on.