Young Stars at the Edge: Stellar Clustering in the Outer Regions of the
  M33 Disk
  We investigate the distribution of bright main sequence stars near the
northern edge of the M33 disk. Clustering on sub-kpc scales is seen among stars
with ages near 10 Myr, and two large star-forming complexes are identified.
Similar large-scale grouping is not evident among stars with ages 100 Myr.
These stars are also distributed over a much larger area than those with
younger ages, and it is argued that random stellar motions alone, as opposed to
orderly motions of the type spurred by large scale secular effects, can
re-distribute stars out to distances of at least 2 kpc (i.e. one disk scale
length) from their birth places on 100 Myr timescales. Such random motions may
thus play a significant role in populating the outer regions of the M33 disk.
Finally, it is suggested that - to the extent that the ambient properties of
the outer disk mirror those in the main body of the disk - stars in this part
of M33 may have formed in star clusters with masses 50 - 250 solar, which is
substantially lower than the peak of the solar neighborhood initial cluster
mass function.
