تقرير
Rotational spectroscopy of CH$_3$OD with a reanalysis of CH$_3$OD toward IRAS 16293$-$2422
العنوان: | Rotational spectroscopy of CH$_3$OD with a reanalysis of CH$_3$OD toward IRAS 16293$-$2422 |
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المؤلفون: | Ilyushin, V. V., Müller, H. S. P., Drozdovskaya, M. N., Jørgensen, J. K., Bauerecker, S., Maul, C., Porohovoi, R., Alekseev, E. A., Dorovskaya, O., Zakharenko, O., Lewen, F., Schlemmer, S., Lees, R. M. |
سنة النشر: | 2024 |
المجموعة: | Astrophysics Physics (Other) |
مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics, Physics - Chemical Physics |
الوصف: | We have started a measurement campaign of numerous methanol isotopologs in low-lying torsional states in order to provide extensive line lists for radio astronomical observations from an adequate spectroscopic model and to investigate how the intricate vibration-torsion-rotation interactions manifest themselves in the spectra of different isotopic species. After CD$_3$OH and CD$_3$OD, we turn our focus to CH$_3$OD, which is an important species for studying deuteration in prestellar cores and envelopes that enshroud protostars. Notably, deuteration is frequently viewed as a diagnostic tool for star formation. The measurements used in this study were obtained in two spectroscopic laboratories and cover large fractions of the 34 GHz--1.35 THz range. As done in previous studies, we employed a torsion-rotation Hamiltonian model for our analysis that is based on the rho-axis method. The resulting model describes the ground and first excited torsional states of CH$_3$OD well up to quantum numbers $J \leqslant 51$ and $K_a \leqslant 18$. We derived a line list for radio astronomical observations from this model that is accurate up to at least 1.35~THz and should be sufficient for all types of radio astronomical searches for this methanol isotopolog in these two lowest torsional states. This line list was applied to a reinvestigation of CH$_3$OD in data from the Protostellar Interferometric Line Survey of IRAS 16293--2422 obtained with the Atacama Large Millimeter/submillimeter Array. The new accurately determined value for the column density of CH$_3$OD implies that the deuteration in methanol differs in its two functional groups by a factor of $\sim$7.5. Comment: 12 pages including figures, tables, references and appendix. Astron. Astrophys., in press |
نوع الوثيقة: | Working Paper |
DOI: | 10.1051/0004-6361/202449918 |
URL الوصول: | http://arxiv.org/abs/2406.08236 |
رقم الأكسشن: | edsarx.2406.08236 |
قاعدة البيانات: | arXiv |
DOI: | 10.1051/0004-6361/202449918 |
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