Arcus: exploring the formation and evolution of clusters, galaxies, and stars

Supermassive black holes (SMBH) interact with gas in the interstellar and intergalactic media (ISM/IGM) in a process termed "feedback" that is key to the formation and evolution of galaxies and clusters. Characterizing the origins and physical mechanisms governing this feedback requires tracing the propagation of outflowing mass, energy and momentum from the vicinity of the SMBH out to megaparsec scales. Our ability to understand the interplay between feedback and structure evolution across multiple scales, as well as a wide range of other important astrophysical phenomena, depends on diagnostics only available in soft X-ray spectra (10-50 angstrom). Arcus combines high-resolution, efficient, lightweight X-ray gratings with silicon pore optics to provide R similar to 2500 with an average effective area of similar to 200 cm(2), an order of magnitude larger than the Chandra gratings. Flight-proven CCDs and instrument electronics are strong heritage components, while spacecraft and mission operations also reuse highly successful designs.