FEEDBACK is a SOFIA legacy program dedicated to study the interaction of massive stars with their environment. It performs a survey of 11 galactic high mass star forming regions in the 158 $\mu$m (1.9 THz) line of CII and the 63 $\mu$m (4.7 THz) line of OI. We employ the 14 pixel LFA and 7 pixel HFA upGREAT instrument to spectrally resolve (0.24 MHz) these FIR structure lines. With an observing time of 96h, we will cover $\sim$6700 arcmin$^2$ at 14.1$''$ angular resolution for the CII line and 6.3$''$ for the OI line. The observations started in spring 2019 (Cycle 7). Our aim is to understand the dynamics in regions dominated by different feedback processes from massive stars such as stellar winds, thermal expansion, and radiation pressure, and to quantify the mechanical energy injection and radiative heating efficiency. The CII line provides the kinematics of the gas and is one of the dominant cooling lines of gas for low to moderate densities and UV fields. The OI line traces warm and high-density gas, excited in photodissociations regions with a strong UV field or by shocks. The source sample spans a broad range in stellar characteristics from single OB stars, to small groups of O stars, to rich young stellar clusters, to ministarburst complexes. It contains well-known targets such as Aquila, the Cygnus X region, M16, M17, NGC7538, NGC6334, Vela, and W43 as well as a selection of HII region bubbles, namely RCW49, RCW79, and RCW120. These CII maps, together with the less explored OI 63 $\mu$m line, provide an outstanding database for the community. They will be made publically available and will trigger further studies and follow-up observations.

中文翻译：

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反馈：用于研究大质量恒星形成区域中恒星反馈的 SOFIA 遗留项目

FEEDBACK 是 SOFIA 的一项遗留项目，致力于研究大质量恒星与其环境的相互作用。它对 CII 的 158 $\mu$m (1.9 THz) 线和 OI 的 63 $\mu$m (4.7 THz) 线中的 11 个银河系高质量恒星形成区域进行了调查。我们使用 14 像素 LFA 和 7 像素 HFA upGREAT 仪器来光谱解析（0.24 MHz）这些 FIR 结构线。观察时间为 96 小时，CII 线的角分辨率为 14.1$''$，OI 线的角分辨率为 6.3$''$，我们将覆盖 $\sim$6700 arcmin$^2$。观测开始于 2019 年春季（第 7 周期）。我们的目标是了解由来自大质量恒星的不同反馈过程（如恒星风、热膨胀和辐射压力）主导的区域的动力学，并量化机械能注入和辐射加热效率。CII 线提供气体的运动学，是用于中低密度和 UV 场的主要气体冷却线之一。OI 线追踪在具有强紫外线场或受到冲击的光解区域中激发的温暖和高密度气体。源样本的恒星特征范围很广，从单颗 OB 星到小群 O 星，再到丰富的年轻星团，再到微型星暴复合体。它包含众所周知的目标，例如 Aquila、Cygnus X 区域、M16、M17、NGC7538、NGC6334、Vela 和 W43，以及精选的 HII 区域气泡，即 RCW49、RCW79 和 RCW120。这些 CII 地图，连同较少探索的 OI 63 $\mu$m 线，为社区提供了一个出色的数据库。它们将被公开，并将引发进一步的研究和后续观察。