Specific dissipative processes that form tight brown dwarf binaries

Identify the specific energy-dissipation mechanisms that enable the formation of tight brown dwarf binaries around stars at separations well below 1 astronomical unit, evaluating the roles of tidal interactions between gaseous envelopes or accretion disks during formation.

Background

Opacity-limited fragmentation suggests primordial separations larger than ~10 AU, implying that significant dynamical and dissipative processes are required to produce tight brown dwarf binaries such as Gliese 229 Ba–Bb with a separation of ~0.042 AU.

The authors suggest tidal interactions as likely contributors but explicitly state that the exact dissipative processes are unclear, motivating targeted theoretical and observational efforts.