Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-08-29
Astronomy and Astrophysics
Astrophysics
Accepted to the Astrophysical Journal; 43 pages, 13 figures
Scientific paper
10.1086/324076
We present a near-infrared extinction study of the dark globule B335, a protostellar collapse candidate, using data from HST/NICMOS and the W.M. Keck Observatory. These data allow a new quantitative test of the "inside-out" collapse model previously proposed to explain molecular line profiles observed toward this region. We find that the shape of the density profile is well matched by the collapse model, but that the amount of extinction corresponds to larger column densities than predicted. An unstable Bonnor-Ebert sphere with dimensionless outer radius xi_max=12.5+/-2.6 provides an equally good description of the density profile, and is indistinguishable from the collapse model over the range in radius sampled by the data. The bipolar outflow driven by 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 opening angle provides a good match to theobservations. The complete exinction map is well reproduced by a model that includes both infall and outflow, and an extra 20% dispersion that likely results from residual turbulent motions. This fitted model has an infall radius of R_inf=26"+/-3"(0.031pc for 250pc distance), and an outflow cone semi-opening angle of alpha=41+/-2 degrees. The fitted infall radius is consistent with those derived from molecular line observations and supports the inside-out collapse interpretation of the density structure. The fitted opening angle of the outflow is slightly larger than observed in CO emission, perhaps because the full extent of the outflow cone in CO becomes confused with ambient core emission at low velocities.
Alves Joao F.
Chen Hua
Harvey Daniel W. A.
Lada Charles J.
Myers Philip C.
No associations
LandOfFree
Structure of Protostellar Collapse Candidate B335 Derived from Near-Infrared Extinction Maps does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Structure of Protostellar Collapse Candidate B335 Derived from Near-Infrared Extinction Maps, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure of Protostellar Collapse Candidate B335 Derived from Near-Infrared Extinction Maps will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-594720