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Title: TESTING MAGNETIC FIELD MODELS FOR THE CLASS 0 PROTOSTAR L1527

For the Class 0 protostar L1527 we compare 131 polarization vectors from SCUPOL/JCMT, SHARP/CSO, and TADPOL/CARMA observations with the corresponding model polarization vectors of four ideal-MHD, nonturbulent, cloud core collapse models. These four models differ by their initial magnetic fields before collapse; two initially have aligned fields (strong and weak) and two initially have orthogonal fields (strong and weak) with respect to the rotation axis of the L1527 core. Only the initial weak orthogonal field model produces the observed circumstellar disk within L1527. This is a characteristic of nearly all ideal-MHD, nonturbulent, core collapse models. In this paper we test whether this weak orthogonal model also has the best agreement between its magnetic field structure and that inferred from the polarimetry observations of L1527. We found that this is not the case; based on the polarimetry observations, the most favored model of the four is the weak aligned model. However, this model does not produce a circumstellar disk, so our result implies that a nonturbulent, ideal-MHD global collapse model probably does not represent the core collapse that has occurred in L1527. Our study also illustrates the importance of using polarization vectors covering a large area of a cloud core tomore » determine the initial magnetic field orientation before collapse; the inner core magnetic field structure can be highly altered by a collapse, and so measurements from this region alone can give unreliable estimates of the initial field configuration before collapse.« less
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ; ;  [5] ; ;  [6] ;  [7] ;  [8] ;  [9] ;  [10]
  1. University of Western Australia, School of Physics, 35 Stirling Highway, Crawley, WA 6009 (Australia)
  2. Astronomy Department, University of Virginia, Charlottesville, VA 22904 (United States)
  3. Astronomy Department and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720-3411 (United States)
  4. SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD, Groningen (Netherlands)
  5. Department of Astronomy, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States)
  6. Northwestern University, Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and the Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States)
  7. Herzberg Astronomy and Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada)
  8. Boston University, Institute for Astrophysical Research, Boston, MA 02215 (United States)
  9. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
  10. University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)
Publication Date:
OSTI Identifier:
22364869
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 797; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; JETS; MAGNETIC CORES; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; POLARIMETRY; POLARIZATION; PROTOSTARS; ROTATION; STAR EVOLUTION; STARS; VECTORS