A TWO MICRON ALL SKY SURVEY ANALYSIS OF THE STABILITY OF SOUTHERN BOK GLOBULES
A TWO MICRON ALL SKY SURVEY ANALYSIS OF THE STABILITY OF SOUTHERN BOK GLOBULES
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南博克小球稳定性的两微米全天勘测分析
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. de la Reza
中科院分区：
文献类型：
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作者：
G. Racca;J. W. Vilas;R. de la Reza
我们使用近红外2微米全天巡天数据，利用NICE方法构建南博克球状体样本的视觉消光图。我们推导出了致密核心的径向消光分布，并分析了它们对引力坍缩的稳定性与等温Bonnor-Ebert球。这些核心的稳定性参数（最大值）的频率分布表明，他们中的大量位于稳定状态，然后突然减少的核心在不稳定状态。这种下降是陡峭的球状体与相关的IRAS点源比无星球状体。此外，处于稳定状态的球具有T = 15 ± 6 K的Bonnor-Ebert温度，而临界加不稳定球的组具有T = 10 ± 3 K的不同温度。对所有球状体的距离进行了估算，并计算了红外天文卫星源的光谱类别。没有发现变化的核心的稳定性参数和光谱类的相关IRAS源。在13 CO J = 1 − 0分子谱线观测的基础上，我们确定并模拟了一个朝向样品小球的蓝色非对称谱线轮廓，得到了0.25 km s−1的上限下落速度。
We used near-infrared Two Micron All Sky Survey data to construct visual extinction maps of a sample of Southern Bok globules utilizing the NICE method. We derived radial extinction profiles of dense cores identified in the globules and analyzed their stability against gravitational collapse with isothermal Bonnor–Ebert spheres. The frequency distribution of the stability parameter (ξmax) of these cores shows that a large number of them are located in stable states, followed by an abrupt decrease of cores in unstable states. This decrease is steeper for globules with associated IRAS point sources than for starless globules. Moreover, globules in stable states have a Bonnor–Ebert temperature of T = 15 ± 6 K, while the group of critical plus unstable globules has a different temperature of T = 10 ± 3 K. Distances were estimated to all the globules studied in this work and the spectral class of the IRAS sources was calculated. No variations were found in the stability parameters of the cores and the spectral class of their associated IRAS sources. On the basis of 13CO J = 1 − 0 molecular line observations, we identified and modeled a blue-asymmetric line profile toward a globule of the sample, obtaining an upper limit infall speed of 0.25 km s−1.