arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0706.4036astro-ph
收藏

经典Be星γ-仙后座周围星周盘的热结构

The Thermal Structure of the Circumstellar Disk Surrounding the Classical Be Star gamma Cassiopeia

T. A. A. Sigut, C. E. Jones

备注：
11 pages, 8 figures high resolution figures available at http://inverse.astro.uwo.ca/sig_jon07.html
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

我们计算了热经典Be星$γ$仙后座周围星周包层中气体的辐射平衡模型。这种计算是使用一个代码，结合了一些改进以前的治疗磁盘的热结构的\citet{mil98}和\citet{jon04} ;最重要的是，加热和冷却速率计算与原子模型的H，He，CNO，Mg，Si，Ca，和Fe及其相关离子。因此，第一次，被磁盘的热结构计算与太阳能的化学成分的气体，而不是假设一个纯氢信封。我们比较预测的平均磁盘温度，总能量损失H $α$，和近红外过量与观测，发现所有可以解释的磁盘是在垂直流体静力平衡与密度在赤道平面的$ρ(R)\approx 3$ $5\cdot 10^{-11} (R/R_*)^{-2.5} \rm g cm^{-3}$。我们还讨论了磁盘的热结构的变化，结果从额外的加热和冷却过程中提供的气体与太阳能的化学成分超过那些提供给纯氢等离子体。

英文摘要：

We have computed radiative equilibrium models for the gas in the circumstellar envelope surrounding the hot, classical Be star $γ$Cassiopeia. This calculation is performed using a code that incorporates a number of improvements over previous treatments of the disk's thermal structure by \citet{mil98} and \citet{jon04}; most importantly, heating and cooling rates are computed with atomic models for H, He, CNO, Mg, Si, Ca, & Fe and their relevant ions. Thus, for the first time, the thermal structure of a Be disk is computed for a gas with a solar chemical composition as opposed to assuming a pure hydrogen envelope. We compare the predicted average disk temperature, the total energy loss in H$α$, and the near-IR excess with observations and find that all can be accounted for by a disk that is in vertical hydrostatic equilibrium with a density in the equatorial plane of $ρ(R)\approx 3$ to $5\cdot 10^{-11} (R/R_*)^{-2.5} \rm g cm^{-3}$. We also discuss the changes in the disk's thermal structure that result from the additional heating and cooling processes available to a gas with a solar chemical composition over those available to a pure hydrogen plasma.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑