用CN 5-4线探测T Tau N的气盘
Probing the gaseous disk of T Tau N with CN 5-4 lines
摘要：
我们提出了光谱分辨赫歇尔/HIFI观测年轻的多系统T头在原子和分子线。虽然CO，H2O，[C II]和SO线跟踪包络线和流出气体的速度高达33公里/秒，相对于系统，CN 5-4超精细结构线在566.7，566.9 GHz显示出一个狭窄的双峰分布中心在系统速度，与T Tau N致密盘的外部区域的起源一致。用热化学程序ProDiMo对T Tau N盘进行盘模拟，得到CN线通量和剖面与观测结果一致，并限制了气体盘的大小（R_out = 110（+10，-20）AU）及其倾角（i = 25 \pm 5度）。该模型表明CN线起源于距恒星40-110 AU处的盘上层，该盘上层受到恒星紫外场的照射并被加热到50-700 K。相对于之前观察到的CN 2-1毫米谱线，CN 5-4谱线似乎受包络发射的影响较小，因为它们的临界密度和激发温度更大。因此，高J CN线是嵌入盘的独特的无混淆示踪剂，例如T Tau N的盘。
英文摘要：
We present spectrally resolved Herschel/HIFI observations of the young multiple system T Tau in atomic and molecular lines. While CO, H2O, [C II], and SO lines trace the envelope and the outflowing gas up to velocities of 33 km/s with respect to systemic, the CN 5-4 hyperfine structure lines at 566.7, 566.9 GHz show a narrow double-peaked profile centered at systemic velocity, consistent with an origin in the outer region of the compact disk of T Tau N. Disk modeling of the T Tau N disk with the thermo-chemical code ProDiMo produces CN line fluxes and profiles consistent with the observed ones and constrain the size of the gaseous disk (R_out = 110 (+10, -20) AU) and its inclination (i = 25 \pm 5 degree). The model indicates that the CN lines originate in a disk upper layer at 40-110 AU from the star, which is irradiated by the stellar UV field and heated up to temperatures of 50-700 K. With respect to previously observed CN 2-1 millimeter lines, the CN 5-4 lines appear to be less affected by envelope emission, due to their larger critical density and excitation temperature. Hence, high-J CN lines are a unique confusion-free tracer of embedded disks, such as the disk of T Tau N.
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。
