Affordable Access

Access to the full text

Dust Emissivity in the Star-Forming Filament OMC 2/3

Authors
  • Sadavoy, S. I.
  • Stutz, A. M.
  • Schnee, S.
  • Mason, B. S.
  • Di Francesco, J.
  • Friesen, R. K.
Type
Preprint
Publication Date
Feb 16, 2016
Submission Date
Jan 25, 2016
Identifiers
DOI: 10.1051/0004-6361/201527364
Source
arXiv
License
Yellow
External links

Abstract

We present new measurements of the dust emissivity index, beta, for the high-mass, star-forming OMC 2/3 filament. We combine 160-500 um data from Herschel with long-wavelength observations at 2 mm and fit the spectral energy distributions across a ~ 2 pc long, continuous section of OMC 2/3 at 15000 AU (0.08 pc) resolution. With these data, we measure beta and reconstruct simultaneously the filtered-out large-scale emission at 2 mm. We implement both variable and fixed values of beta, finding that beta = 1.7 - 1.8 provides the best fit across most of OMC 2/3. These beta values are consistent with a similar analysis carried out with filtered Herschel data. Thus, we show that beta values derived from spatial filtered emission maps agree well with those values from unfiltered data at the same resolution. Our results contradict the very low beta values (~ 0.9) previously measured in OMC 2/3 between 1.2 mm and 3.3 mm data, which we attribute to elevated fluxes in the 3.3 mm observations. Therefore, we find no evidence or rapid, extensive dust grain growth in OMC 2/3. Future studies with Herschel data and complementary ground-based long-wavelength data can apply our technique to obtain robust determinations of beta in nearby cold molecular clouds.

Report this publication

Statistics

Seen <100 times