Gaps, rings, and spirals in scattered light: Discs observed around Herbig Ae/Be and T-Tauri stars

行星形成于环绕着新形成的原恒星的气体和尘埃盘中。不断增长的行星吸积盘物质，产生环形间隙，盘/行星引力相互作用导致盘结构中的螺旋波。由于原行星本身在这个早期阶段基本上是无法探测到的，这些大规模的扰动被认为是正在进行的行星形成的指纹。虽然在太阳系的尺度上，这些行星形成盘可能非常大（延伸到100天文单位），但最近的这样的物体大约在100秒差距之外。因此，从地球上看，一个行星形成盘可能只对着一个角秒。幸运的是，我们目前正处于高分辨率仪器的黄金时代，使我们能够以前所未有的细节探测原行星盘的结构。我们的团队很幸运地获得了这些所谓的过渡盘的大样本数据，这些数据是用Gemini的GPI和VLT的SPHERE等仪器获得的。这个项目的目的是使用我们复杂的辐射传输代码TORUS来模拟这些丰富的观测数据。这些模型将使我们能够确定原行星盘的结构以及其中尘埃的成分，从而帮助我们确定行星形成的必要条件。

Planets form in the discs of gas and dust that encircle newly formed protostars. The growing planets accrete disc material, creating annular gaps, and the disc/planet gravitational interaction results in spiral waves in the disc structure. Since the protoplanet itself is essentially undetectable at this early stage it is these large-scale perturbations that are regarded as the fingerprints of on-going planet formation.Although on solar system scales these planet-forming discs may be very large (extending to many 100 AUs) the nearest such objects are on the order of 100 parsecs away. Thus a planet-forming disc may only subtend an arcsecond as seen from the Earth. Fortunately we are currently in a golden age of high-resolution instrumentation enabling us to probe the structure of protoplanetary discs in unprecedented detail. Our team is fortunate to have data on a large sample of these so-called transitional discs, taken with instruments such as Gemini's GPI and the VLT's SPHERE.The aim of this project is to model this wealth of observational data using our sophisticated radiative-transfer code TORUS. These models will enable us to determine the structure of the protoplanetary discs as well as the composition of the dust within them, and will thus help us to identify the conditions necessary for planet formation.