Athena Wide Field Imager Key Science Drivers

TL;DR

The Athena Wide Field Imager aims to address key astrophysical questions such as black hole formation, galaxy cluster heating, and stellar black hole spins through advanced survey capabilities and high-resolution observations.

Contribution

This paper outlines the science objectives and instrument requirements for the Athena WFI, highlighting its capabilities for wide-area surveys and detailed astrophysical studies.

Findings

Designed for excellent point source sensitivity and grasp

Enables detailed studies of galaxy clusters and compact objects

Supports high-count rate capability with low pile-up

Abstract

The Wide Field Imager (WFI) is one of two instruments for the Advanced Telescope for High-ENergy Astrophysics (Athena). In this paper we summarise three of the many key science objectives for the WFI - the formation and growth of supermassive black holes, non-gravitational heating in clusters of galaxies, and spin measurements of stellar mass black holes - and describe their translation into the science requirements and ultimately instrument requirements. The WFI will be designed to provide excellent point source sensitivity and grasp for performing wide area surveys, surface brightness sensitivity, survey power, and absolute temperature and density calibration for in-depth studies of the outskirts of nearby clusters of galaxies and very good high-count rate capability, throughput, and low pile-up, paired with very good spectral resolution, for detailed explorations of bright Galactic compact objects.