  Context: Several observations of protoplanetary disks display
non-axisymmetric features, often interpreted as vortices. Numerical modeling
has repeatedly shown that gap-opening planets are capable of producing large
and long-lasting vortices at their outer gap edge, making massive planets
popular candidates as the source of such features. Aims: We explore the
lifetime of vortices generated by Jupiter-sized planets as a function of the
thermal relaxation timescale, the level of turbulence, and the effect of disk
self-gravity. Methods: We conduct 2D numerical simulations using the
hydrodynamics codes PLUTO and FARGO, scanning through several physical and
numerical parameters. Vortex properties are automatically extracted from
thousands of simulation snapshots. Results: We find that vortices that spawn at
the outer gap edge can survive for about 100-3000 planetary orbits, with the
shortest lifetimes occurring for moderately efficient dissipation and cooling.
However, we also observe a different regime of long-lasting vortices with
lifetimes of at least 15 000 orbits for very low viscosity and very short
thermal relaxation timescales. Disk self-gravity significantly shortens the
lifetime of regular vortices but still allows long-lived ones to survive.
Conclusions: Our results suggest that the cooling timescale plays an important
role in vortex formation and lifetime and that planet-generated vortices should
be observable at large distances from the star for typical thermal relaxation
timescales and low turbulence levels.
