A Bimodal Inclination Distribution in Main KB (?!?!?!?)

Three groups have presented arguments for a bimodal inclination distribution in the main KB
(Levison & Stern 2001; Brown 2001; Kavelaars et al).

• Levison & Stern (2001):
  • Argues for a correlations between inclination and absolute magnitude.
    • Big guys have higher i's!
  • Only 0.1% chance that the i-distribution of H<6.5 objects is the same as H>6.5.
  • Does not appear to be the result of observational biases.
  • The distributions are the same for i>5^O.
    • Implies a superposition of a hot and cold population.
    • Cold population have H>6.5 and i<5^O.
  
  
  
  
• So how did this happen? ........... I can think of only one way:
  • Start with a cold disk. Accretion occurs faster closer in so bigger objects are closer in.
  • A large object (say Neptune-sized) is delivered to the inner regions of disk, say Q~40AU.
  • Inner disk objects are scattered outward and then the planet moves on.
  • In the outer regions of the disk, the hot objects formed closer in, so can be larger.
  • Sounds like Thommes et al., but they do not get high enough inclinations!