Leiden Observatory, Leiden University, Leiden, Netherlands.
Science. 2013 Jun 7;340(6137):1199-202. doi: 10.1126/science.1236770.
The statistics of discovered exoplanets suggest that planets form efficiently. However, there are fundamental unsolved problems, such as excessive inward drift of particles in protoplanetary disks during planet formation. Recent theories invoke dust traps to overcome this problem. We report the detection of a dust trap in the disk around the star Oph IRS 48 using observations from the Atacama Large Millimeter/submillimeter Array (ALMA). The 0.44-millimeter-wavelength continuum map shows high-contrast crescent-shaped emission on one side of the star, originating from millimeter-sized grains, whereas both the mid-infrared image (micrometer-sized dust) and the gas traced by the carbon monoxide 6-5 rotational line suggest rings centered on the star. The difference in distribution of big grains versus small grains/gas can be modeled with a vortex-shaped dust trap triggered by a companion.
已发现的系外行星统计数据表明行星的形成效率很高。然而，仍存在一些尚未解决的基本问题，例如在行星形成过程中，原行星盘中的颗粒向内漂移过多。最近的理论提出了尘埃陷阱来克服这个问题。我们利用阿塔卡马大型毫米/亚毫米波阵（ALMA）的观测结果，报告了在恒星 Oph IRS 48 周围的盘中尘埃陷阱的探测结果。在 0.44 毫米波长连续谱图上，在恒星的一侧显示出高对比度的新月形发射，其来源于毫米级大小的颗粒，而中红外图像（微米级大小的尘埃）和一氧化碳 6-5 转动线追踪的气体则表明存在以恒星为中心的环。大颗粒与小颗粒/气体的分布差异可以通过伴星触发的漩涡状尘埃陷阱来建模。
