Collision strengths for FIR and UV transtions in PIII and the phosphorus abundance
| Autor: | Rahla Naghma, Sultana N. Nahar, Anil K. Pradhan |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences FOS: Physical sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Planetary nebula Exoplanet Spectral line Supernova Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Abundance (ecology) 0103 physical sciences Emissivity Production (computer science) Ground state 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences |
| DOI: | 10.48550/arxiv.1806.01358 |
| Popis: | Phosphorus abundance is crucial for DNA-based extraterrestrial life in exoplanets. Atomic data for observed spectral lines of P-ions are needed for its accurate determination. We present the first calculations for collision strengths for the forbidden PIII fine structure transition $3s^23p (^2P^o_{1/2-3/2})$ within the ground state at 17.9 $\mu$m, as well as allowed UV transitions in the $3s^23p (^2P^o_{1/2,3/2}) \rightarrow 3s3p^2 (^2D_{3/2,5/2}, ^2S_{1/2}, ^2P_{1/2,3/2})$ multiplets between 915-1345 $\AA$. Collision strengths are computed using the Breit-Pauli R-Matrix method including the first 18 levels, and they exhibit extensive auto-ionizing resonance structures. In particular, the Maxwellian averaged effective collision strength for the FIR 17.9 $\mu$m transition shows a factor 3 temperature variation broadly peaking at typical nebular temperatures. Its theoretical emissivity with solar phosphorus abundance is computed relative to H$\beta$ and found to be similar to observed intensties from planetary nebulae; the abundances derived in earlier works are 3-5 times sub-solar. The results pertain to the reported paucity of phosphorus from preferred production sites in supernovae, and abundances in planetary nebulae and supernova remnants. Comment: To appear in Mon. Not. Royal Astron. Soc. Letters, 5 pages, 3 figures |
| Databáze: | OpenAIRE |
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