The COordinated Molecular Probe Line Extinction Thermal Emission Survey of Star Forming Regions
Comparing Column Density Tracers in Molecular Clouds
Alyssa Goodman, Scott Schnee, Naomi Ridge
Scott L. Schnee, T. Bethell, Alyssa A. Goodman, "Estimating Column Density in Molecular Clouds Using Far-IR and Sub-mm Emission Maps", 2006, ApJ, 640, L47. .
Scott L. Schnee, Naomi A. Ridge, Alyssa A. Goodman, Jason G. Li, "A COMPLETE Look at the use of IRAS Emission Maps to Estimate Extinction and Dust Temperature". 2005, ApJ, 634, 442.
Intercomparison of column density maps based on 13CO integrated intensity, far-infrared dust emission, and near-infrared extinction mapping reveals that: extinction mapping is most intrinsically accurate; far-infrared emission maps can be custom-corrected to nearly match extinction maps (see panel at right); but 13CO maps cannot be corrected to represent column density faithfully. The 13CO emission is subject to both opacity and depletion effects at high column densities, and is sub-thermally excited at low column density, leading to column density maps that are impressionistically, but not quantitatively, accurate. The near-infrared and thermal emission maps show that, at least over the 10-square pc area of Perseus mapped in COMPLETE, the distribution of column density is log-normal, as predicted by many theories of turbulence.
COMPLETE Web Master: Sarah Block • COMPLETE PI: Alyssa Goodman
This material is based upon work supported by the National Science Foundation under Grant No. AST-0407172.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s)
and do not necessarily reflect the views of the National Science Foundation.
Document URL: www.cfa.harvard.edu/COMPLETE/projects/coldens.html
Last Modified: Thursday, 08-Mar-2012 10:07:01 EST