Cold debris disks around nearby stars

行星系统有多常见的问题对天体物理学来说是至关重要的。赫歇尔空间天文台的关键方案“邻近恒星周围的尘埃”（DUNES）将解决年轻恒星周围的盘中行星/行星系统形成的普遍性问题。这是一个系统的搜索计划，寻找暗淡、寒冷的碎片盘，以发现太阳附近的小行星系统的发生率。更具体地说，DUNES是一个灵敏度和体积有限（d < 25 pc）的调查133颗恒星的年龄~ 0.1 ~ 10 Gyr和光谱类型F，G和K的拟议项目的目标是执行一个核心部分的DUNES观测分析。核心任务是模拟沙丘目标的热再发射，并尽可能地模拟额外的可观测量（例如，多波长图像、偏振测量），以便约束盘结构和灰尘性质。通过与沙丘联盟内的其他团队合作，该模型将能够得出有关星子形成对恒星质量的依赖性、星子带的碰撞和动力学演化以及尘埃盘存在与行星存在之间可能存在的相关性的结论。

The question of how common planetary systems are is of fundamental importance for astrophysics. The Herschel Space Observatory key program “Dust around nearby stars” (DUNES) will address the question about the universality of planets/planetary systems formation in disks around young stars. It is a systematic search program for faint, cold debris disks to find the fractional incidence of planetesimal systems in the solar neighbourhood. More specifically, DUNES is a sensitivity- and volume-limited (d < 25 pc) survey of 133 stars of age ~ 0.1 to ~ 10 Gyr and spectral types F, G, and K.The goal of the proposed project is to perform a central part of the analysis of the DUNES observations. The core task is to model the thermal reemission of the DUNES targets and – as far as available – additional observables (e.g., multi-wavelength images, polarization measurements) in order to constrain the disk structure and dust properties. In collaboration with the other teams within the DUNES consortium this modeling will allow to derive conclusions about the dependence of the planetesimal formation on the stellar mass, the collisional and dynamical evolution of planetesimal belts and possible correlations between the existence of dust disks and the presence of planets.