高能暂现源 · 每日文献综述

SUNRISE III is a stratospheric balloon-borne solar observatory with a 1 m diameter telescope and three postfocus instruments, along with an image stabilisation system, all within a protective gondola. It samples the lower solar atmosphere, from the solar surface to the middle chromosphere, at a resolution approaching 50 km on the Sun. SUNRISE III flew successfully for 6.5 days suspended from a zero-pressure stratospheric balloon from northern Sweden to northwestern Canada in 2024 July, gathering around 200 TB of data. The present issue of the Astrophysical Journal Letters focuses on the first scientific results from the data collected during that flight. This Letter introduces this Focus Issue, providing a very brief overview of the capabilities of the instrumentation, the flight, and of the gathered data. Challenges for the measurements, data reduction, and interpretation are also briefly touched upon. The Letter ends with an overview of the first set of science results obtained from these data, as presented in the current Focus Issue.

Gravitational-wave detection provides humanity with unique access to extreme astrophysical and cosmological phenomena. In space-based missions, however, the Doppler frequency pulling induced by orbital motion severely limits the precise extraction of gravitational-wave signals. This work shows that by introducing properly designed low-pass filters into established laser arm-locking systems, it is possible to maintain a high suppression ratio of laser frequency noise while drastically reducing Doppler pulling. Moreover, with the proposed scheme, the arm-locking system can precisely predict the Doppler frequency without the need to know the real-time distance between satellites, thereby greatly simplifying the complexity of hardware implementation. These results can be generalized and applied to other arm-locking configurations operating in more complex multi-perturbation environments.