Academic Journal
Preprint typeset using L ATEX style emulateapj v. 03/07/07 VLTI/MIDI 10 MICRON INTERFEROMETRY OF THE FORMING MASSIVE STAR W33A
| العنوان: | Preprint typeset using L ATEX style emulateapj v. 03/07/07 VLTI/MIDI 10 MICRON INTERFEROMETRY OF THE FORMING MASSIVE STAR W33A |
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| المؤلفون: | W. J. De Wit, M. G. Hoare, R. D. Oudmaijer, J. C. Mottram |
| المساهمون: | The Pennsylvania State University CiteSeerX Archives |
| المصدر: | http://arxiv.org/pdf/0711.0437v1.pdf. |
| سنة النشر: | 2008 |
| المجموعة: | CiteSeerX |
| الوصف: | We report on resolved interferometric observations with VLTI/MIDI of the massive young stellar object (MYSO) W33A. The MIDI observations deliver spectrally dispersed visibilities with values between 0.03 and 0.06, for a baseline of 45m over the wavelength range 8-13µm. The visibilities indicate that W33A has a FWHM size of approximately 120AU (0.030”) at 8µm which increases to 240AU at 13µm, scales previously unexplored among MYSOs. This observed trend is consistent with the temperature falling off with distance. 1D dust radiative transfer models are simultaneously fit to the visibility spectrum, the strong silicate feature and the shape of the mid infrared spectral energy distribution (SED). For any powerlaw density distribution, we find that the sizes (as implied by the visibilities) and the stellar luminosity are incompatible. A reduction to a third of W33A’s previously adopted luminosity is required to match the visibilities; such a reduction is consistent with new high resolution 70µm data from Spitzer’s MIPSGAL survey. We obtain best fits for models with shallow dust density distributions of r −0.5 and r −1.0 and for increased optical depth in the silicate feature produced by decreasing the ISM ratio of graphite to silicates and using optical grain properties by Ossenkopf et al. (1992). |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.4214; http://arxiv.org/pdf/0711.0437v1.pdf |
| الاتاحة: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.315.4214 http://arxiv.org/pdf/0711.0437v1.pdf |
| Rights: | Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| رقم الانضمام: | edsbas.45E1C363 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |