Spectra of phosphorus ions for astrophysical modeling: P~I - P~XV

Abstract

Phosphorus (P), a basic element of life, has been a least studied element due to its poor presence in astrophysical spectra. However, search for the P lines has increased considerably with discoveries of exoplanets and are being detected by high resolution and sophisticated astronomical observatories, e.g. James Webb Space Telescope (JWST). JWST may provide a clue for life with detection of P in its infrared (IR) region. Identification of the element and analysis of the observed spectra will require high accuracy data for atomic processes that produces lines and their predicted features. The present study focuses on these needs and reports systematically regions of wavelengths, from x-ray to IR, that show prominent lines by the 15 individual ionization stages of phosphorus, P I - P XV for the first time. We present large amount of relevant atomic data for energies, transition parameters, and lifetimes obtained in relativistic Breit-Pauli approximation using the R-matrix method and atomic structure program SUPERSTRUCTURE. Our spectral features for the fifteen ions, P I - P XV, predict strengths of lines in various wavelength regions. They show dominance of P~I and P~II in the infrared region and other ions in the ultraviolet and optical regions often stretching to IR in the continuum. For determination of accuracy, we have made extensive comparisons of our atomic data with available experimental and theoretical values. Based on these, our results and features are expected to provide precise plasma diagnostics and astrophysical modeling.