Spectroscopic diagnostics of low-ionized iron-peak elements. Electron-impact excitation of Ni${}^{3+}$ and photoionisation of Ni${}^{2+}$

Luis Fernández-Menchero, Ryan T. Smyth, Catherine A. Ramsbottom +1

The spectra from Fe-peak elements may be used to determine the temperature and density of various astrophysical objects. Determination of these quantities is underpinned by the acc…