  The nearby young star beta Pictoris hosts a rich and complex planetary
system, with at least two giant planets and a nearly edge-on debris disk that
contains several dynamical subpopulations of planetesimals. While the inner
ranges of the debris disk have been studied extensively, less information is
known about the outer, fainter parts of the disk. Here we present an analysis
of archival FORS V-band imaging data from 2003-2004, which have previously not
been explored scientifically because the halo substructure of the bright
stellar point spread function is complex. Through a high-contrast scheme based
on angular differential imaging, with a forward-modelling approach to mitigate
self-subtraction, we produced the deepest imaging yet for the outer range of
the beta Pic disk, and extracted its morphological characteristics. A
brightness asymmetry between the two arms of the edge-on disk, which was
previously noted in the inner disk, is even more pronounced at larger angular
separations, reaching a factor ~10 around 1000 AU. Approaching 2000 AU, the
brighter arm is visible at a surface brightness of 27-28 mag/arcsec^2. Much
like for the brightness asymmetry, a tilt angle asymmetry exists between the
two arms that becomes increasingly extreme at large separations. The outer tilt
angle of 7.2 deg can only be explained if the outer disk is farther from an
edge-on inclination than the inner disk, or if its dust has a stronger
scattering anisotropy, or (most likely) both. The strong asymmetries imply the
presence of a highly eccentric kinematic disk component, which may have been
caused by a disruptive event thought to have taken place at a closer-in
location in the disk.
