The Structure of NGC 1976 in the Radio Range
High angular resolution radio continuum images of NGC 1976 (M42, Orion A) at frequency=330 MHz (wavelength=91 cm), 1.5 GHz (20 cm) and 10.6 GHz (2.8 cm), have been aligned, placed on a common grid, smoothed to common resolutions of 80" (=0.16 pc at 420 pc) and 90" (=0.18 pc) and compared o...
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Published in | arXiv.org |
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Main Authors | , , |
Format | Paper Journal Article |
Language | English |
Published |
Ithaca
Cornell University Library, arXiv.org
20.10.2011
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Subjects | |
Online Access | Get full text |
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Summary: | High angular resolution radio continuum images of NGC 1976 (M42, Orion A) at frequency=330 MHz (wavelength=91 cm), 1.5 GHz (20 cm) and 10.6 GHz (2.8 cm), have been aligned, placed on a common grid, smoothed to common resolutions of 80" (=0.16 pc at 420 pc) and 90" (=0.18 pc) and compared on a position-by-position basis. The results are not consistent with a single value of Te. Rather, there is a significant variation, from Te =6000K in the low intensity, extended region to Te=8500K in the higher intensity, more compact region. The best fit to the data is a multi-layer model obtained from radio recombination line (RRL) data. An estimate of temperature fluctuations from the model yields t2=0.003. This is a factor of 10 lower than fluctuation values from optical O++ line data. |
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ISSN: | 2331-8422 |
DOI: | 10.48550/arxiv.1110.4521 |