XRISM science requirements

The XRISM mission is being designed to fulfill the following main scientific requirements (SO=Science Objective):

• (SO-1) In order to investigate "Structure formation of the Universe and evolution of clusters of galaxies", XRISM shall reveal spatial distribution and their dissipation of thermal and non-thermal energy of the largest gravitationally bounded system | clusters of galaxies, and directly observe sites of their growth mechanism from both thermo-dynamic and kinematic aspects.
• (SO-2) In order to investigate "Circulation history of baryonic matters in the Universe", XRISM shall trace baryon cycles in various stages from element synthesis by stellar objects and supernovae to material dissipation in interstellar to intergalactic space, and directly observe the element abundance evolution in the cosmic structure formation.
• (SO-3) In order to investigate "Transport and circulation of energy in the Universe", XRISM shall reveal matter and energy feedback by galaxies and active galaxies, and observe its impact to the co-evolution of galaxies and supper-massive black holes.
• (SO-4) In order to realize "New science with unprecedented high resolution X-ray spectroscopy, XRISM shall develop new methods of plasma diagnostics, and measurements of velocity and gravitational redshift shown in spectra of materials around relativistic objects to pioneer new horizon of X-ray astrophysics.

 A White paper was prepared by members of the XRISM Science Team for the benefit of the general astronomical community. This paper describes the capabilities of XRISM, offers a sampling of the many science topics that the mission will address, and discusses the synergies of XRISM with the plethora of planned and existing facilities in the 2020s and beyond.

 The quick reference document provides a synthetic view of the main scientific and technological advancements of XRISM.