skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds

Abstract

Density profiles of isolated cores derived from thermal dust continuum emission rely on models of dust properties, such as mass opacity, that are poorly constrained. With complementary measures from near-infrared extinction maps, we can assess the reliability of commonly used dust models. In this work, we compare Herschel -derived maps of the optical depth with equivalent maps derived from CFHT WIRCAM near-infrared observations for three isolated cores: CB 68, L 429, and L 1552. We assess the dust opacities provided from four models: OH1a, OH5a, Orm1, and Orm4. Although the consistency of the models differs between the three sources, the results suggest that the optical properties of dust in the envelopes of the cores are best described by either silicate and bare graphite grains (e.g., Orm1) or carbonaceous grains with some coagulation and either thin or no ice mantles (e.g., OH5a). None of the models, however, individually produced the most consistent optical depth maps for every source. The results suggest that either the dust in the cores is not well-described by any one dust property model, the application of the dust models cannot be extended beyond the very center of the cores, or more complex SED fitting functions are necessary.

Authors:
;  [1];  [2];  [3]; ; ;  [4];  [5];  [6]
  1. Department of Physics and Astronomy, 3800 Finnerty Road, University of Victoria, Victoria, BC, V8P 5C2 (Canada)
  2. National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada)
  3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  4. Max-Planck-Institut für Astronomy, Königstuhl 17, D-69117, Heidelberg (Germany)
  5. Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
  6. Departmento de Astronomìa, Facultad Ciencias Físicas y Matemáticas, Universidad de Concepción, Av. Esteban Iturra s/n Barro Universitario, Casilla 160-C, Concepción (Chile)
Publication Date:
OSTI Identifier:
22679720
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 849; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CLOUDS; COMPARATIVE EVALUATIONS; COSMIC DUST; COSMIC GASES; DENSITY; EMISSION; GRAPHITE; ICE; MASS; OPACITY; RELIABILITY; SILICATES

Citation Formats

Webb, K. A., Thanjavur, K., Di Francesco, J., Sadavoy, S., Launhardt, R., Vicente, J. Abreu, Kainulainen, J., Shirley, Y., and Stutz, A., E-mail: kawebb@uvic.ca. Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA901C.
Webb, K. A., Thanjavur, K., Di Francesco, J., Sadavoy, S., Launhardt, R., Vicente, J. Abreu, Kainulainen, J., Shirley, Y., & Stutz, A., E-mail: kawebb@uvic.ca. Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds. United States. doi:10.3847/1538-4357/AA901C.
Webb, K. A., Thanjavur, K., Di Francesco, J., Sadavoy, S., Launhardt, R., Vicente, J. Abreu, Kainulainen, J., Shirley, Y., and Stutz, A., E-mail: kawebb@uvic.ca. Wed . "Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds". United States. doi:10.3847/1538-4357/AA901C.
@article{osti_22679720,
title = {Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds},
author = {Webb, K. A. and Thanjavur, K. and Di Francesco, J. and Sadavoy, S. and Launhardt, R. and Vicente, J. Abreu and Kainulainen, J. and Shirley, Y. and Stutz, A., E-mail: kawebb@uvic.ca},
abstractNote = {Density profiles of isolated cores derived from thermal dust continuum emission rely on models of dust properties, such as mass opacity, that are poorly constrained. With complementary measures from near-infrared extinction maps, we can assess the reliability of commonly used dust models. In this work, we compare Herschel -derived maps of the optical depth with equivalent maps derived from CFHT WIRCAM near-infrared observations for three isolated cores: CB 68, L 429, and L 1552. We assess the dust opacities provided from four models: OH1a, OH5a, Orm1, and Orm4. Although the consistency of the models differs between the three sources, the results suggest that the optical properties of dust in the envelopes of the cores are best described by either silicate and bare graphite grains (e.g., Orm1) or carbonaceous grains with some coagulation and either thin or no ice mantles (e.g., OH5a). None of the models, however, individually produced the most consistent optical depth maps for every source. The results suggest that either the dust in the cores is not well-described by any one dust property model, the application of the dust models cannot be extended beyond the very center of the cores, or more complex SED fitting functions are necessary.},
doi = {10.3847/1538-4357/AA901C},
journal = {Astrophysical Journal},
number = 1,
volume = 849,
place = {United States},
year = {Wed Nov 01 00:00:00 EDT 2017},
month = {Wed Nov 01 00:00:00 EDT 2017}
}