• quasar outflow
• molecular clump
• quasar
• AGN

Recent observations of active galaxies show that a large amount of outflowing gas is in molecular form up to a radius of about 1 kpc. Molecular gas is expected to form in outflows beacuse of hydrodynamical instabilities at the interface between the black hole wind and the interstellar medium, presumably in the form of clumps. In this
work, we study how the structure of an hydrogen clump changes while it is carried
with the outflow and exposed to quasar radiation, assuming spherical geometry and
a Bonnor-Ebert density profile. We expect the clump to present an H2 core, surrounded by an atomic shell and an ionized shell. Thus, we investigate the propagation and interaction of shock and rarefaction waves which originate at the discontinuities between different layers. We show that the molecular core contracts to densities 3 orders of magnitude higher thant its initial density and after that it starts
an expansion phase, which allows radiation to penetrate further inside, until the
clump is completely evaporated. We estimate clump lifetimes of the order of 1 Myr,
implying that after its formation molecular gas can travel 1 - 2 kpc in SMBHs of
10^8 solar masses accreting at Eddington rate.