Deep Near-Infrared Survey of the Pipe Nebula II: Data, Methods, and Dust
  Extinction Maps
  We present a new set of high resolution dust extinction maps of the nearby
and essentially starless Pipe Nebula molecular cloud. The maps were constructed
from a concerted deep near-infrared imaging survey with the ESO-VLT, ESO-NTT,
CAHA 3.5m telescopes, and 2MASS data. The new maps have a resolution three
times higher than the previous extinction map of this cloud by Lombardi et al.
(2006) and are able to resolve structure down to 2600 AU. We detect 244
significant extinction peaks across the cloud. These peaks have masses between
0.1 and 18.4 M_sun, diameters between 1.2 and 5.7e4 AU (0.06 and 0.28 pc), and
mean densities of about 1e4 cm${^-3}$, all in good agreement with previous
results. From the analysis of the Mean Surface Density of Companions we find a
well defined scale near 1.4e4 AU below which we detect a significant decrease
in structure of the cloud. This scale is smaller than the Jeans Length
calculated from the mean density of the peaks. The surface density of peaks is
not uniform but instead it displays clustering. Extinction peaks in the Pipe
Nebula appear to have a spatial distribution similar to the stars in Taurus,
suggesting that the spatial distribution of stars evolves directly from the
primordial spatial distribution of high density material.
