2004/10/20 by Jason D. Fiege, Doug Johnstone, Russell O. Redman +1 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.1086/424956
published as Astrophys.J. 616 (2004) 925-942 · To appear in Ap.J. Dec. 1 edition, volume 616. 40 pages and 42 figures. Figures are severely reduced to satisfy astro-ph size limits. A version with higher quality figures is available by contacting the first author
arxiv created 2004/10/20 · openalex publication_date 2004/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
The G11.11-0.12 infrared-dark cloud has a filamentary appearance, both in extinction against the diffuse infrared emission of the Galactic plane and in emission at 850 μm. We use a novel computational technique based on an advanced genetic algorithm to explore thoroughly three different models of self-gravitating, pressure-truncated filaments and to constrain their parameters. Specifically, the models tested are the nonmagnetic Ostriker model, a generalized version of the magnetic Stodólkiewicz model, and the magnetic Fiege & Pudritz model. Previous results showed that G11.11-0.12 has a much steeper ~ r -4 radial density profile than other filaments, where the density varies approximately as r -2 , and that this steep density profile is consistent with the Ostriker model. We present a more complete analysis that shows that the radial structure of G11.11-0.12 is consistent with regimes of each of these models. All of the magnetic models that agree with the data are threaded by a dominant poloidal magnetic field, and most have dynamically significant fields. Thus, G11.11-0.12 is an excellent candidate for radial support by a magnetic field that is predominantly poloidal. We predict the polarization patterns expected for both magnetic models and show that the two magnetic models produce different polarization patterns that should be distinguished by observations.