IRC +10216的最内层信封--eSMA的观点
IRC+10216's Innermost Envelope -- The eSMA's View
摘要：
我们使用扩展亚毫米波阵列（eSMA）在其最扩展的配置，以调查IRC+10216的最里面（半径为290 R*）的拱星包络（CSE）。我们使用HCN和其他分子线对CSE进行成像，光束尺寸为0。“22x0。“46，深入到包层的最内边缘（15 R*），那里的膨胀速度只有3公里/秒。讨论了热HCN和KCl脉泽谱线的激发机制。HCN脉泽成分的空间分辨的第一次在一个天文物体上。我们确定了包络中的两个离散区域：半径为的区域。15 R*，其中分子种类刚刚形成并且气体已经开始加速（区域I），以及具有半径23 R* 和厚度15 R* 的壳区域（区域II），其膨胀速度已经达到高达13 km/s，接近15 km/s的终极速度。在I区探测到的Si $^{34}$ S线显示出由于强的机翼成分而产生的16 km/s的大膨胀速度，表明发射可能来自最内层包层的激波区。在区域II中，P.A.最大的质量损失方向是120 +/- 10度，这可能对应于恒星的赤道方向。区域II包含类似圆环的特征。这两个区域的出现可能是由于这两个区域中尘埃颗粒的尺寸分布存在显着差异。
英文摘要：
We used the Extended Submillimeter Array (eSMA) in its most extended configuration to investigate the innermost (within a radius of 290 R* from the star) circumstellar envelope (CSE) of IRC+10216. We imaged the CSE using HCN and other molecular lines with a beam size of 0."22 x 0."46, deeply into the very inner edge (15 R*) of the envelope where the expansion velocity is only 3 km/s. The excitation mechanism of hot HCN and KCl maser lines is discussed. HCN maser components are spatially resolved for the first time on an astronomical object. We identified two discrete regions in the envelope: a region with a radius of . 15 R*, where molecular species have just formed and the gas has begun to be accelerated (region I) and a shell region (region II) with a radius of 23 R* and a thickness of 15 R*, whose expansion velocity has reached up to 13 km/s, nearly the terminal velocity of 15 km/s. The Si$^{34}$S line detected in region I shows a large expansion velocity of 16 km/s due to strong wing components, indicating that the emission may arise from a shock region in the innermost envelope. In region II, the P.A. of the most copious mass loss direction was found to be 120 +/- 10 degrees, which may correspond to the equatorial direction of the star. Region II contains a torus-like feature. These two regions may have emerged due to significant differences in the size distributions of the dust particles in the two regions.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
