WG1: Large-scale structure of the Universe.

This WG will coordinate investigations on how NewAthena can enable advancement in our understanding of the hot gas that permeates structures in the Universe at intergalactic and larger scales. This includes groups and clusters of galaxies, as well as feedback of accreting supermassive black holes in Active Galactic Nuclei (AGN) onto the intra-cluster medium. At the core of the scientific purview of this WG is the study of the hot gas origin, chemical composition and physical properties as a probe of large-scale structure formation and evolution.

WG2: Galaxies and supermassive black holes.

This WG will encompass NewAthena studies of galaxies and their AGN, and their coevolution at all scales, including the geometry and origin of the X-ray emitting regions, the energetics, incidence and effects of AGN outflows, the effects of kinetic and radiative AGN feedback and of stellar feedback on their host galaxies, and AGN population studies up to high redshift to put constraints on the seeds and growth mechanisms of supermassive black holes.

WG3: Stars and their environment.

This WG will coordinate the study of prospective NewAthena observations of stars (stellar activity, colliding winds, magnetospheric accretion, mass loss, to mention just a few examples), their planetary systems and star-planet interactions, supernova remnants, and the physics and chemistry of the Interstellar Medium.

WG4: Compact objects.

This WG will coordinate scientific activities related to NewAthena studies of compact objects — white dwarfs (WDs), neutron stars (NSs), and black holes (BHs) — in the Milky Way and nearby galaxies. The main focus will be on extreme systems both in isolation and within binary systems. This includes, e.g. pulsars, magnetars, central compact objects, the potential detection of isolated black holes, cataclysmic variables, low-mass and high-mass X-ray binaries hosting neutron stars and black holes, transitional and classical millisecond pulsars, and ultra-luminous X-ray sources.

WG5: Transients and multi-messenger astrophysics.

This WG will coordinate the study of the “transient universe” with NewAthena. This will include the determination of the astrophysical nature of the most common celestial sources of neutrinos and gravitational waves, as well as non-persistent electromagnetic sources, such as e.g. supernovae explosions, tidal disruption events, and gamma ray bursts.

WG6: Cosmology and fundamental physics.

This WG will coordinate studies employing X-ray observations with NewAthena to constrain cosmological parameters (e.g. using clusters or quasars); probe particle physics beyond the standard model; perform tests of general relativity (e.g. through accretion processes in the strong gravity regime or via X-ray counterparts to gravitational wave sources); alongside any other studies that address our fundamental models of physics. It is anticipated that many science projects will use the astrophysical objects that are the focus of other WGs, and thus overlap with those efforts.

WG7: Science Support.

This WG will provide assistance to the NASC, notably through supporting the theory and simulation effort required to assess the expected mission performance. This transverse WG will aid in undertaking and optimising synthetic observations of a wide variety of high-energy astrophysical sources, and will investigate novel analysis techniques appropriate to NewAthena data. Scientists involved in the development of software for the reduction and scientific analysis of NewAthena data, the planning of the calibration activities and of the corresponding facilities, or in the monitoring of the instrument scientific performance are also encouraged to contribute with their expertise.