  Cool-core clusters (e.g., Perseus or M87) often possess a network of bright
gaseous filaments, observed in radio, infrared, optical and X-ray bands. We
propose that these filaments are powered by the reconnection of the magnetic
field in the wakes of buoyant bubbles. AGN-inflated bubbles of relativistic
plasma rise buoyantly in the cluster atmosphere, stretching and amplifying the
field in the wake to values of $\displaystyle \beta =8\pi P_{gas}/B^2\sim 1$.
The field lines in the wake have opposite directions and are forced together as
the bubble motion stretches the filament. This setup bears strong similarity to
the coronal loops on the Sun or to the Earth's magneto-tail. The reconnection
process naturally explains both the required level of local dissipation rate in
filaments and the overall luminosity of filaments. The original source of power
for the filaments is the potential energy of buoyant bubbles, inflated by the
central AGN.
