1.3mm polarized emission in the circumstellar disk of a massive protostar
| Autor: | Fernández-López, M., Stephens, I. W., Girart, J. M., Looney, L., Curiel, S., Segura-Cox, D., Eswaraiah, C., Lai, S. -P. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/0004-637X/832/2/200 |
| Popis: | We present the first resolved observations of the 1.3mm polarized emission from the disk-like structure surrounding the high-mass protostar Cepheus A HW2. These CARMA data partially resolve the dust polarization, suggesting an uniform morphology of polarization vectors with an average position angle of 57 degrees and an average polarization fraction of 2.0%. The distribution of the polarization vectors can be attributed to (1) the direct emission of magnetically aligned grains of dust by a uniform magnetic field, or (2) the pattern produced by the scattering of an inclined disk. We show that both models can explain the observations, and perhaps a combination of the two mechanisms produce the polarized emission. A third model including a toroidal magnetic field does not match the observations. Assuming scattering is the polarization mechanism, these observations suggest that during the first few 10000 years of high-mass star formation, grain sizes can grow from 1 to several 10s micron. Comment: Accepted for publication in ApJ, 9 pages, 5 figures, 2 tables |
| Databáze: | arXiv |
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