The NewAthena mission concept in the context of the next decade of X-ray astronomy
Large X-ray observatories such as Chandra and XMM-Newton have been deliveringscientific breakthroughs in research fields as diverse as our Solar System, theastrophysics of stars, stellar explosions and compact objects, accretingsuper-massive black holes, and large-scale structures traced by the hot plasmapermeating and surrounding galaxy groups and clusters. The recently launchedobservatory XRISM is opening in earnest the new observational window ofnon-dispersive high-resolution spectroscopy. However, several quests are leftopen, such as the effect of the stellar radiation field on the habitability ofnearby planets, the Equation-of-State regulating matter in neutron stars, theorigin and distribution of metals in the Universe, the processes driving thecosmological evolution of the baryons locked in the gravitational potential ofDark Matter and the impact of supermassive black hole growth on galaxyevolution, just to mention a few. Furthermore, X-ray astronomy is a key playerin multi-messenger astrophysics. Addressing these quests experimentallyrequires an order-of-magnitude leap in sensitivity, spectroscopy and surveycapabilities with respect to existing X-ray observatories. This papersuccinctly summarizes the main areas where high-energy astrophysics is expectedto contribute to our understanding of the Universe in the next decade anddescribes a new mission concept under study by the European Space Agency, thescientific community worldwide and two International Partners (JAXA and NASA),designed to enable transformational discoveries: NewAthena. This conceptinherits its basic payload design from a previous study carried out until 2022,Athena.