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ID: 607175.0, MPI für Astronomie / Publikationen_mpia
Observational constraints on submillimeter dust opacity
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Date of Publication (YYYY-MM-DD):2011
Journal Abbrev.:The Astrophysical Journal
Volume:728
Issue / Number:2
Audience:Not Specified
Abstract / Description:Infrared extinction maps and submillimeter dust continuum maps are powerful probes of the density structure in the envelope of star-forming cores. We make a direct comparison between infrared and submillimeter dust continuum observations of the low-mass Class 0 core, B335, to constrain the ratio of submillimeter to infrared opacity (ÃÂºsmm/ÃÂºir) and the submillimeter opacity power-law index (ÃÂº vprop ÃÂ»-ÃÂ²). Using the average value of theoretical dust opacity models at 2.2 ÃÂ¼m, we constrain the dust opacity at 850 and 450 ÃÂ¼m. Using new dust continuum models based upon the broken power-law density structure derived from interferometric observations of B335 and the infall model derived from molecular line observations of B335, we find that the opacity ratios are \frac{\kappa _{850}}{\kappa _{2.2}} = (3.21{--}4.80)^{+0.44}_{-0.30} \times 10^{-4} and \frac{\kappa _{450}}{\kappa _{2.2}} = (12.8{--}24.8)^{+2.4}_{-1.3} \times 10^{-4}with a submillimeter opacity power-law index of ÃÂ²smm = (2.18-2.58)+0.30 -0.30. The range of quoted values is determined from the uncertainty in the physical model for B335. For an average 2.2 ÃÂ¼m opacity of 3800 ÃÂ± 700 cm2 g-1, we find a dust opacity at 850 and 450 ÃÂ¼m of ÃÂº850 = (1.18-1.77)+0.36 -0.24 and ÃÂº450 = (4.72-9.13)+1.9 -0.98 cm2 g-1 of dust. These opacities are from (0.65-0.97)ÃÂºOH5 850 of the widely used theoretical opacities of Ossenkopf and Henning for coagulated ice grains with thin mantles at 850 ÃÂ¼m.
Free Keywords:dust; extinction; ISM: clouds; stars: formation
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
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