KINEMATICS AND PHYSICAL CONDITIONS OF THE INNERMOST ENVELOPE IN B335
KINEMATICS AND PHYSICAL CONDITIONS OF THE INNERMOST ENVELOPE IN B335
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B335 最内层包络线的运动学和物理条件
DOI：
10.1088/0004-637x/742/1/57
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
N. Ohashi
中科院分区：
文献类型：
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作者：
Hsi;S. Takakuwa;N. Ohashi
我们利用亚毫米波阵列和单碟观测数据，拍摄了B335周围原恒星包层的C18 O（2-1）和CS（7-6）图像，其空间动态范围为10000 ~ 1400 Au。C18 O的发射显示了一个扩展的（10,000 Au）结构以及一个紧凑的（1500 Au）成分集中在原恒星的位置。CS辐射显示原恒星周围有一个紧凑的（约900 Au）成分，加上一个沿着东西方向拉长的类似晕的（约3000 Au）结构。在更高的速度下（|ΔV| CS的辐射比C18 O的辐射更强，范围更广。通过大速度梯度模型检查了包络的物理条件。在|ΔV| 0.3 km s-1，气体温度高于（>40 K），|ΔV|气体密度小于0.3 km s−1，而气体密度则较低（<106 cm−3）。我们认为，温度较高，密度较低的气体，|ΔV| 0.3 km s-1与相关的外流有关，而温度较低、密度较高的气体在|ΔV| 0.3 km s−1是包络分量。通过对速度通道图中的位置偏移的检查，B335中包层旋转的特定角动量的径向分布在半径从104到102 Au处被揭示。比角动量减小到半径为370 Au，然后在该半径内似乎是守恒的。一个可能的情况下的演变的信封旋转进行了讨论。
We made C18O (2–1) and CS (7–6) images of the protostellar envelope around B335 with a high spatial dynamic range from ∼10,000 to ∼400 AU by combining the Submillimeter Array and single-dish data. The C18O emission shows an extended (∼10,000 AU) structure as well as a compact (∼1500 AU) component concentrated at the protostellar position. The CS emission shows a compact (∼900 AU) component surrounding the protostar, plus a halo-like (∼3000 AU) structure elongated along the east–west direction. At higher velocities (|ΔV| ≳ 0.3 km s−1), the CS emission is stronger and more extended than the C18O emission. Physical conditions of the envelope were examined through a Large Velocity Gradient model. At |ΔV| ≳ 0.3 km s−1, the gas temperature is higher (>40 K) than that at |ΔV| ≲ 0.3 km s−1, whereas the gas density is lower (<106 cm−3). We consider that the higher temperature and lower density gas at |ΔV| ≳ 0.3 km s−1 is related to the associated outflow, while the lower temperature and higher density gas at |ΔV| ≲ 0.3 km s−1 is the envelope component. From the inspection of the positional offsets in the velocity channel maps, the radial profile of the specific angular momentum of the envelope rotation in B335 was revealed at radii from ∼104 down to ∼102 AU. The specific angular momentum decreases down to a radius of ∼370 AU, and then appears to be conserved within that radius. A possible scenario of the evolution of envelope rotation is discussed.