UK APAP Network

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Plasmas permeate our Universe, being present in stellar atmospheres, interstellar gas clouds in galaxies, planetary nebulae, supernova remnants, black hole accretion disks, and so on.Spectroscopy of all these objects has shown a richness of information, inparticular in the spectral lines that are emitted by the ions that are present in the plasmas.In recent years, an overwhelming amount of XUV spectroscopic data have beenobtained from the satellite missions such as SOHO, Hinode, STEREO, SDO, IRIS (solar) and Chandra, XMM-Newton, HST, FUSE(non-solar), while upcoming and future missions such as Solar Orbiter, XRISM, \& ATHENA will provide no let-up.The state of matter in each object --- the distribution of temperature and density, chemical composition --- can be determined through diagnostic analysis of spectral data in which models, incorporating the full physics of the object, confront the observations.In addition, seismology of stellar interiors, including our sun, are a unique probe of their structure.Spectroscopy and seismology information are fundamental for our understanding of the origin and evolution of the Universe.Collisions of electrons and photons with atoms, ions and molecules play a fundamental role incharacterizing astrophysical plasmas, and it is therefore necessary that accurate atomic data are calculatedand incorporated into atomic databases of plasma models.It might be surprising, but a large fraction of the spectra produced by ions is still unexplored.Large discrepancies between observations and theory are also still present.In recent years, we have shown the need to perform accurate calculations ofelectron-ion collisions for individual ions, in order to solve the large, long-standingdiscrepancies between observed and calculated line intensities in collisional (astrophysical and laboratory) plasmas.Furthermore, there is also a long standing problem concerning the elemental abundance of our sun.It is thought to be due to our incomplete understanding of how low light emerges from deep in its interior.In X-ray astrophysics, we still have gaps in our understanding of outflows in active galactic nuclei,especially the density of the outflows. This limits our estimation of the kinetic power, thus, the impactof the outflows to the host galaxy.We propose calculations which will enable the interpretation of spectraldata from satellites and stellar seismology which will further our understanding of the solar corona, stellar atmospheres,supernova remnants, nebulae and stars.We will also development of the photoionized plasma model in SPEX toenable density diagnostics of N-like to F-like ions with metastable absorption lines. We will analyzeX-ray low-energy grating spectra to quantify the density and power of ionized outflows in activegalactic nuclei.With this proposal, we aim to strengthen the collaboration betweenexperimental, observational and theoretical research. Our work will also impact upon the magnetic fusionprogram and its quest for a safe, reliable and environmentally friendly energy source.