EXPANDED VERY LARGE ARRAY OBSERVATIONS OF THE BARNARD 5 STAR-FORMING CORE: EMBEDDED FILAMENTS REVEALED
EXPANDED VERY LARGE ARRAY OBSERVATIONS OF THE BARNARD 5 STAR-FORMING CORE: EMBEDDED FILAMENTS REVEALED
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扩展的巴纳德 5 星形成核心的超大阵列观测：揭示了嵌入的细丝
DOI：
10.1088/2041-8205/739/1/l2
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
S. Corder
中科院分区：
文献类型：
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作者：
J. Pineda;A. Goodman;H. Arce;P. Caselli;S. Longmore;S. Corder
本文报道了英仙座Barnard 5区NH_3（1，1）辐射的46.6 ′ × 8′扩展甚大阵（EVLA）镶嵌观测结果，角分辨率为6″。这张图覆盖了相干区域，在那里稠密气体呈现亚音速非热运动（如用绿色班克望远镜（GBT）进行的单碟观测所见）。EVLA和GBT的联合观测首次揭示了在这个低质量恒星形成区域中的一个引人注目的行星结构（20“宽或5000 Au，距离英仙座）。这种结构的综合强度分布与流体静力平衡中的等温细丝模型一致。观测到的核心中心区域的B5-IRS 1年轻恒星天体（YSO）与北方无星凝聚体之间的距离与稠密气体的金斯长度相匹配。这表明相干区中的致密气体正在碎裂。所观察到的区域显示出狭窄的速度分散，其中大部分气体显示出亚音速湍流的证据，并且存在很少的空间变化。它只是接近YSO，在那里发现速度分散增加，但仍然显示亚音速非热运动。
We present ∼6.′5 × 8′ Expanded Very Large Array (EVLA) mosaic observations of the NH3 (1,1) emission in the Barnard 5 region in Perseus, with an angular resolution of 6″. This map covers the coherent region, where the dense gas presents subsonic non-thermal motions (as seen from single dish observations with the Green Bank Telescope, GBT). The combined EVLA and GBT observations reveal, for the first time, a striking filamentary structure (20″ wide or 5000 AU at the distance of Perseus) in this low-mass star-forming region. The integrated intensity profile of this structure is consistent with models of an isothermal filament in hydrostatic equilibrium. The observed separation between the B5–IRS1 young stellar object (YSO), in the central region of the core, and the northern starless condensation matches the Jeans length of the dense gas. This suggests that the dense gas in the coherent region is fragmenting. The observed region displays a narrow velocity dispersion, where most of the gas shows evidence for subsonic turbulence and where little spatial variations are present. It is only close to the YSO where an increase in the velocity dispersion is found, but still displaying subsonic non-thermal motions.