DISK IMAGING SURVEY OF CHEMISTRY WITH SMA. II. SOUTHERN SKY PROTOPLANETARY DISK DATA AND FULL SAMPLE STATISTICS
DISK IMAGING SURVEY OF CHEMISTRY WITH SMA. II. SOUTHERN SKY PROTOPLANETARY DISK DATA AND FULL SAMPLE STATISTICS
复制标题
使用 SMA 进行磁盘化学成像调查。
DOI：
10.1088/0004-637x/734/2/98
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
J. Kastner
中科院分区：
文献类型：
--
作者：
K. Öberg;C. Qi;J. Fogel;E. Bergin;S. Andrews;C. Espaillat;D. Wilner;I. Pascucci;J. Kastner
这是基于DISS数据的系列论文中的第二篇，DISS是一个亚毫米阵列观测计划，旨在从空间和光谱上解析12个原行星圆盘的化学成分。我们给出了六个南方天源的数据--IM LUP，SAO 206462(HD 135344b)，HD 142527，AS209，AS205和V4046SGR--它们补充了之前报道的金牛座恒星形成区的六个源。CO2-1和HCO+3-2的排放在所有的圆盘上都被探测和分辨，并显示出与开普勒式旋转相一致的速度模式。DCO+3-2、N2H+3-2、H2CO30 3−20 2和41 4−31 3、HCN 3-2和CN 23 3/4/2−12 2/3/1的发射也基本上是空间分辨的。M星和K星的探测效率最高，而F星SAO 206462只有微弱的CN和HCN发射，而HD 142527只探测到H_2CO。这些发现与之前金牛座星盘的统计数据一起支持这样一种假设，即许多小分子的高探测率取决于冷的和受保护的盘中板的存在，与M和K星相比，这在F和A星周围不太常见。尽管光谱类型和吸积率有两个数量级的范围，但建议的辐射示踪剂CN/HCN的圆盘平均变化很小。相反，解析的图像表明，在至少两个系统中，CN/HCN发射比随盘半径的变化而变化。经典/全T Tauri盘和过渡盘在盘化学上没有明显的观测差异。此外，观测到的谱线发射并不取决于测量的吸积光度或检测到的红外谱线的数量，这表明100AU以外的化学与驱动最内部少数AU化学的物理过程没有耦合。
This is the second in a series of papers based on data from DISCS, a Submillimeter Array observing program aimed at spatially and spectrally resolving the chemical composition of 12 protoplanetary disks. We present data on six Southern sky sources—IM Lup, SAO 206462 (HD 135344b), HD 142527, AS 209, AS 205, and V4046 Sgr—which complement the six sources in the Taurus star-forming region reported previously. CO 2–1 and HCO+ 3–2 emission are detected and resolved in all disks and show velocity patterns consistent with Keplerian rotation. Where detected, the emission from DCO+ 3–2, N2H+ 3–2, H2CO 30 3 − 20 2 and 41 4 − 31 3, HCN 3–2, and CN 23 3/4/2 − 12 2/3/1 are also generally spatially resolved. The detection rates are highest toward the M and K stars, while the F star SAO 206462 has only weak CN and HCN emission, and H2CO alone is detected toward HD 142527. These findings together with the statistics from the previous Taurus disks support the hypothesis that high detection rates of many small molecules depend on the presence of a cold and protected disk midplane, which is less common around F and A stars compared to M and K stars. Disk-averaged variations in the proposed radiation tracer CN/HCN are found to be small, despite a two orders of magnitude range of spectral types and accretion rates. In contrast, the resolved images suggest that the CN/HCN emission ratio varies with disk radius in at least two of the systems. There are no clear observational differences in the disk chemistry between the classical/full T Tauri disks and transitional disks. Furthermore, the observed line emission does not depend on the measured accretion luminosities or the number of infrared lines detected, which suggests that the chemistry outside of 100 AU is not coupled to the physical processes that drive the chemistry in the innermost few AU.