تقرير
The Gas-Rich Circumbinary Disk of HR 4049. II: A Detailed Study of the Near-Infrared Spectrum
| العنوان: | The Gas-Rich Circumbinary Disk of HR 4049. II: A Detailed Study of the Near-Infrared Spectrum |
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| المؤلفون: | Malek, Sarah E., Cami, Jan |
| سنة النشر: | 2014 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | HR 4049 is a peculiar evolved binary which is surrounded by a circumbinary disk. Mid-infrared observations show that the disk is rich in molecular gas and radially extended. To study the properties of this disk, we re-analyzed a set of near-infrared observations at high spectral resolution obtained with Gemini-Phoenix. These data cover absorption lines originating from the first overtone of CO and from \hoh in the 2.3 $\mu$m region as well as more complex emission-absorption profiles from \hoh and the fundamental mode of CO near 4.6 $\mu$m. By using an excitation diagram and from modeling the spectrum, we find that most of the CO overtone and \hoh absorption originates from hot gas ($T_{\rm ex} \approx 1000$~K) with high column densities, consistent with the mid-infrared data. The strong emission in the wavelength range of the CO fundamental furthermore suggests that there is a significant quantity of gas in the inner cavity of the disk. In addition, there is a much colder component in the line of sight to the disk. A detailed analysis of the overtone line profiles reveals variations in the line widths which are consistent with a radially extended disk in Keplerian rotation with hotter gas closer to the central star. We estimate the mass of the primary to be $\sim 0.34$~M$_{\odot}$ and discuss the implications for its evolutionary status. Comment: 9 pages, 5 figures. Accepted for publication in the Astrophysical Journal |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/0004-637X/794/2/113 |
| URL الوصول: | http://arxiv.org/abs/1408.5173 |
| رقم الأكسشن: | edsarx.1408.5173 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/0004-637X/794/2/113 |
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