标题： 10微米高对比度成像，对以下恒星周围的系外行星进行搜索：Eps Indi A、Eps Eri、Tau Ceti、Sirius A和Sirius B 显示英文标题

标题： High contrast imaging at 10 microns, a search for exoplanets around: Eps Indi A, Eps Eri, Tau Ceti, Sirius A and Sirius B

摘要： 直接成像岩石状系外行星是即将问世的大型望远镜的主要科学目标之一。 成像这类行星的对比度要求具有挑战性。 然而，中红外（红外线）波段提供了最佳对比度，以直接探测太阳邻域内系外行星的热信号。 我们旨在利用自适应光学辅助下新开发的快速斩波技术，寻找太阳邻域内明亮恒星周围的系外行星的热信号。 我们使用升级后的VISIR（甚大望远镜中红外成像和光谱仪）仪器，该仪器具备优化用于10~$\mu$m观测的高对比度成像（HCI）能力，以寻找五颗附近（$d$ < 4 pc）恒星周围的系外行星。 与标准VISIR相比，在给定的信噪比和时间条件下，该仪器在N波段的信噪比提高了$\sim$4倍。 在这项工作中，我们实现了亚毫焦耳/秒的检测灵敏度，这足以检测附近系统中的几个木星质量的行星。 尽管没有发现任何天体，但我们获得的最敏感限制在$<2''$范围内，比之前的活动更为敏感。 对于$\epsilon$ Indi A和$\epsilon$ Eri，我们实现的检测极限非常接近由径向速度发现的巨大行星，其中对$\epsilon$ Indi A的限制目前是最敏感的。 我们未能检测到$\epsilon$，因此支持了其较老的年龄。 这里展示的结果表明了中红外波段高对比度成像和系外行星探测的潜力。 显示英文摘要

摘要： The direct imaging of rocky exoplanets is one of the major science goals for upcoming large telescopes. The contrast requirement for imaging such planets is challenging. However, the mid-IR (InfraRed) regime provides the optimum contrast to directly detect the thermal signatures of exoplanets in our solar neighbourhood. We aim to exploit novel fast chopping techniques newly developed for astronomy with the aid of adaptive optics to look for thermal signatures of exoplanets around bright stars in the solar neighbourhood. We use the upgraded VISIR (Very Large Telescope Imager and Spectrometer for the mid-InfraRed) instrument with high contrast imaging (HCI) capability optimized for observations at 10~$\mu$m to look for exoplanets around five nearby ($d$ < 4 pc) stars. The instrument provides an improved signal-to-noise (S/N) by a factor of $\sim$4 in the N-band compared to standard VISIR for a given S/N and time. In this work we achieve a detection sensitivity of sub-mJy, which is sufficient to detect few Jupiter mass planets in nearby systems. Although no detections are made we achieve most sensitive limits within $<2''$ for all the observed targets compared to previous campaigns. For $\epsilon$ Indi A and $\epsilon$ Eri we achieve detection limits very close to the giant planets discovered by RV, with the limits on $\epsilon$ Indi A being the most sensitive to date. Our non-detection therefore supports an older age for $\epsilon$ Indi A. The results presented here show the promise for high contrast imaging and exoplanet detections in the mid-IR regime.