论文标题
51 OPH周围的碎屑盘中原子气的组成，激发和物理状态
The Composition, Excitation, and Physical State of Atomic Gas in the Debris Disk Surrounding 51 Oph
论文作者
论文摘要
我们在紫外线中测量了304个吸收特征和Star 51 OPH的可见光谱，该光谱具有高倾斜度的碎屑盘。我们分析了通过电子通过光学泵送和碰撞激发来维持的激发原子的相对种群，我们发现大多数气体位于恒星的约6AU，具有电子密度$ 10^5 <n（e）<n（e）<n（e）<3 \ 3 \ 3 \ times 10^6 {\ rm cm cm cm cm cm cm cm}^$ 3} $ 3} $ 3} $ 3}^}^}^^^^^^}我们的解释表明，气体是部分离子化的，中性氢的柱密度等于$ 10^{21} \，{\ rm cm}^{ - 2} $，并且具有类似于轻度耗尽的星际培养基或木工 - 木制 - 木制 - 木制 - 木制 - 木制 - 木制 - 木制comets的组成。与其他一些恒星（例如$β$ pic和49 CET）周围的磁盘的结果相比，我们发现中性碳很少。没有检测到分子特征，这表明我们的视线错过了磁盘的分子富含中心平面。我们能够通过氧原子检测到星光的共振散射来证实磁盘的倾斜度。
We measured 304 absorption features in the ultraviolet and visible spectra of the star 51 Oph, which is known to have a debris disk with a high inclination. We analyzed the relative populations of atoms in excited fine-structure and metastable levels that are maintained by optical pumping and collisional excitation by electrons, and we found that most of the gas is situated at about 6AU from the star, has an electron volume density $10^5 < n(e) < 3\times 10^6{\rm cm}^{-3}$, and a temperature T=8000K. Our interpretations reveal that the gas is partly ionized, has a column density of neutral hydrogen equal to $10^{21}\,{\rm cm}^{-2}$, and has a composition similar to that of a mildly depleted interstellar medium or that of Jupiter-family comets. Compared to results for disks around some other stars, such as $β$ Pic and 49 Cet, we find surprisingly little neutral carbon. No molecular features were detected, which indicates that our line of sight misses the molecule-rich central plane of the disk. The tilt of the disk is also validated by our being able to detect resonant scattering of the starlight by oxygen atoms.
