INITIAL CONDITIONS FOR STAR FORMATION IN CLUSTERS: PHYSICAL AND KINEMATICAL STRUCTURE OF THE STARLESS CORE Oph A-N6
INITIAL CONDITIONS FOR STAR FORMATION IN CLUSTERS: PHYSICAL AND KINEMATICAL STRUCTURE OF THE STARLESS CORE Oph A-N6
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DOI：
10.1088/0004-637x/745/2/117
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发表时间：
2011-11
期刊：
影响因子：
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通讯作者：
T. Bourke;P. Myers;P. Caselli;J. di Francesco;A. Belloche;R. Plume;D. Wilner
中科院分区：
文献类型：
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作者：
T. Bourke;P. Myers;P. Caselli;J. di Francesco;A. Belloche;R. Plume;D. Wilner
我们在大部分核心区域呈现高空间（0.05）。Oph A-N6长轴上的N2H+柱密度分布由一个等温圆柱体很好地表示，温度为20 K，峰值密度为7.1 × 106 cm−3，N2H+丰度为2.7 × 10−10。Oph a - n6的质量估计为0.29 M☉，而等温柱体分析的值为0.18 M☉，而等温柱体破碎的临界质量为0.63 M☉。与孤立的低质量岩心相比，Oph a - n6显示出相似的窄线宽度和较小的速度变化，氘分数与“演化”的致密岩心相似。与孤立岩心相比，其体积明显较小，峰柱和体积密度较大。现有的证据表明，蛇夫A- n6是通过蛇夫A灯丝的碎片形成的，是一颗低质量恒星的前身。尘埃连续体的发射表明它可能已经开始形成一颗恒星。
We present high spatial (0.05 over much of the core. The N2H+ column density profile across the major axis of Oph A-N6 is well represented by an isothermal cylinder, with temperature 20 K, peak density 7.1 × 106 cm−3, and N2H+ abundance 2.7 × 10−10. The mass of Oph A-N6 is estimated to be 0.29 M☉, compared to a value of 0.18 M☉ from the isothermal cylinder analysis, and 0.63 M☉ for the critical mass for fragmentation of an isothermal cylinder. Compared to isolated low-mass cores, Oph A-N6 shows similar narrow line widths and small velocity variation, with a deuterium fraction similar to “evolved” dense cores. It is significantly smaller than isolated cores, with larger peak column and volume density. The available evidence suggests that Oph A-N6 has formed through the fragmentation of the Oph A filament and is the precursor to a low-mass star. The dust continuum emission suggests that it may already have begun to form a star.