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We present a near-infrared extinction study of the dark globule B335, aprotostellar collapse candidate, using data from HST/NICMOS and the W.M. KeckObservatory. These data allow a new quantitative test of the "inside-out"collapse model previously proposed to explain molecular line profiles observedtoward this region. We find that the shape of the density profile is wellmatched by the collapse model, but that the amount of extinction corresponds tolarger column densities than predicted. An unstable Bonnor-Ebert sphere withdimensionless outer radius xi_max=12.5+/-2.6 provides an equally gooddescription of the density profile, and is indistinguishable from the collapsemodel over the range in radius sampled by the data. The bipolar outflow drivenby the embedded YSO has an important effect on the extinction through the core,and modeling the outflow as a hollowed-out bipolar cone of constant openingangle provides a good match to theobservations. The complete exinction map iswell reproduced by a model that includes both infall and outflow, and an extra20% dispersion that likely results from residual turbulent motions. This fittedmodel has an infall radius of R_inf=26"+/-3"(0.031pc for 250pc distance), andan outflow cone semi-opening angle of alpha=41+/-2 degrees. The fitted infallradius is consistent with those derived from molecular line observations andsupports the inside-out collapse interpretation of the density structure. Thefitted opening angle of the outflow is slightly larger than observed in COemission, perhaps because the full extent of the outflow cone in CO becomesconfused with ambient core emission at low velocities.Comment: Accepted to the Astrophysical Journal; 43 pages, 13 figure

Structure of Protostellar Collapse Candidate B335 Derived from Near‐Infrared Extinction Maps