arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0908.2997astro-ph.EPastro-ph.IM
收藏

模拟来自原行星盘的AU尺度线成像的一种新的光线跟踪器

A new raytracer for modeling AU-scale imaging of lines from protoplanetary disks

Klaus M. Pontoppidan, Rowin Meijerink, Cornelis P. Dullemond, Geoffrey A. Blake

摘要:

形成现今太阳系的物质起源于内太阳星云的供给区,该区域距离太阳约20天文单位,被称为行星形成区。陨石和彗星物质包含了丰富的证据,证明在太阳系形成的富气阶段,行星形成带中存在着丰富而活跃的化学物质。人们很自然地猜想,在附近年轻恒星周围的原行星盘动物园中,也能找到类似物。研究行星形成的化学和动力学需要:1)100-1000 K的致密气体示踪剂,2)这种示踪剂的成像能力为5-100(0.5-20 AU)毫角秒分辨率,对应于最近恒星形成区距离的行星形成区。认识到丰富的红外(2-200微米)分子光谱最近发现是常见的原行星盘代表这样的示踪剂,我们提出了一个新的通用射线跟踪代码,RADLite,这是优化的红外线光谱和图像的轴对称结构。RADLite可以始终如一地处理各种速度梯度,例如原行星盘内部区域的典型速度梯度。该代码的目的是作为化学和激发代码的后端,并可以快速生成数千条线的光谱,用于模型网格与观测结果进行比较。这种辐射转移工具对于限制行星形成区域的结构和化学性质至关重要,包括来自当前红外成像光谱仪的数据,并扩展到阿塔卡马大型毫米波阵列和下一代超大望远镜,詹姆斯韦伯太空望远镜及其他望远镜。

英文摘要:

The material that formed the present-day Solar System originated in feeding zones in the inner Solar Nebula located at distances within ~20 AU from the Sun, known as the planet-forming zone. Meteoritic and cometary material contain abundant evidence for the presence of a rich and active chemistry in the planet-forming zone during the gas-rich phase of Solar System formation. It is a natural conjecture that analogs can be found amoung the zoo of protoplanetary disks around nearby young stars. The study of the chemistry and dynamics of planet formation requires: 1) tracers of dense gas at 100-1000 K and 2) imaging capabilities of such tracers with 5-100 (0.5-20 AU) milli-arcsec resolution, corresponding to the planet-forming zone at the distance of the closest star-forming regions. Recognizing that the rich infrared (2-200 micron) molecular spectrum recently discovered to be common in protoplanetary disks represents such a tracer, we present a new general raytracing code, RADLite, that is optimized for producing infrared line spectra and images from axisymmetric structures. RADLite can consistently deal with a wide range of velocity gradients, such as those typical for the inner regions of protoplanetary disks. The code is intended as a backend for chemical and excitation codes, and can rapidly produce spectra of thousands of lines for grids of models for comparison with observations. Such radiative transfer tools will be crucial for constraining both the structure and chemistry of planet-forming regions, including data from current infrared imaging spectrometers and extending to the Atacama Large Millimeter Array and the next generation of Extremely Large Telescopes, the James Webb Space Telescope and beyond.

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。

↑