星前核的多方气体静力学模型  

The Polytropic Static Gas Model of Prestellar Core

作　　者：李大磊[1] LI Da-lei(XinJiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China)

机构地区：[1]中国科学院新疆天文台,乌鲁木齐830011

出　　处：《天文学进展》2022年第2期221-227,共7页Progress In Astronomy

基　　金：新疆维吾尔自治区自然科学基金青年项目(2017D01B53)。

摘　　要：星前核是研究恒星形成初始条件和恒星形成极早期阶段的重要样本。密度和温度是描述星前核最基本的两个物理参数,也是利用非局域热动平衡辐射转移计算方法研究分子激发条件和计算分子柱密度,进行天体化学模拟计算所必需的物理参数。Barnard 68(B68)是一个非常典型的星前核,它具有类似球形的结构,非常适合用来检验球对称的理论模型。在球对称的坐标系中,利用多方的气体静力学模型拟合了B68的尘埃消光数据,模型给出的星前核B68的质量为0.8 M⊙。与之前等温的气体静力学模型相比,该模型不仅能拟合尘埃的消光数据,且拟合结果与B68中气体非等温分布的观测结果相符,另外与压强的观测数据也符合得很好。Prestellar core is important to improve our understanding about the initial conditions and the earliest stage of star formation. Density and temperature are the basic physical parameters to characterize the prestellar core, and also are two required input physical parameters to study excitation conditions and estimate the column densities of molecular lines under non local thermodynamic equilibrium, and run the astrochemical models. Barnard 68(B68) is a typical prestellar core and its structure is quite similar with a sphere, which makes it a proper source to test star formation models. Under the spherical coordinate system,the extinction data of B68 is fitted using polytropic static gas model, which gives a mass of 0.8 M⊙ for B68. Compared to the previous isothermal static gas model, the model adopted here not only can fit the dust extinction data very well, but also agrees with the observational non-uniform gas temperature, and furthermore can meet the observational pressure.

关 键 词：分子云核 恒星形成 星前核 流体力学 

分 类 号：P142.9[天文地球—天体物理]