Population Properties of Brown Dwarf Analogs to Exoplanets
  We present a kinematic analysis of 152 low surface gravity M7-L8 dwarfs by
adding 8 parallaxes, 38 radial velocities, and 19 proper motions. We find 39
objects to be high-likelihood or bona fide members of nearby moving groups, 92
objects to be ambiguous members and 21 objects that are non-members. We find
that gravity classification and photometric color separate 5-150 Myr sources
from > 3 Gyr field objects, but they do not correlate one-to-one with the
narrower 5 -150 Myr age range. The absolute magnitudes of low-gravity sources
from J band through W3 show a flux redistribution when compared to equivalent
field sources that is correlated with spectral subtype. Clouds, which are a far
more dominant opacity source for L dwarfs, are the likely cause. On CMDs, the
latest-type low-gravity L dwarfs drive the elbow of the L/T transition up to 1
mag redder and 1 mag fainter than field dwarfs at M_J but are consistent with
or brighter than the elbow at M_W1 and M_W2. Furthermore, there is an
indication on CMD's (such as M_J versus (J-W2) of increasingly redder sequences
separated by gravity classification. Examining bolometric luminosities for
planets and low-gravity objects, we confirm that young M dwarfs are
overluminous while young L dwarfs are normal compared to the field. This
translates into warmer M dwarf temperatures compared to the field sequence
while lower temperatures for L dwarfs.
