Implications of infalling Fe II - emitting clouds in active galactic
  nuclei: anisotropic properties
  We investigate consequences of the discovery that Fe II emission in quasars,
one of the spectroscopic signatures of "Eigenvector 1", may originate in
infalling clouds. Eigenvector 1 correlates with the Eddington ratio L/L_Edd so
that Fe II/Hbeta increases as L/L_Edd increases. We show that the "force
multiplier", the ratio of gas opacity to electron scattering opacity, is ~ 10^3
- 10^4 in Fe II-emitting gas. Such gas would be accelerated away from the
central object if the radiation force is able to act on the entire cloud. As
had previously been deduced, infall requires that the clouds have large column
densities so that a substantial amount of shielded gas is present. The critical
column density required for infall to occur depends on L/L_Edd, establishing a
link between Eigenvector 1 and the Fe II/Hbeta ratio. We see predominantly the
shielded face of the infalling clouds rather than the symmetric distribution of
emitters that has been assumed. The Fe II spectrum emitted by the shielded face
is in good agreement with observations thus solving several long-standing
mysteries in quasar emission lines.
