Biosignatures & Paleobiology

Biosignature Line Ratios Of [P II] In Exoplanetary And Nebular Environments

By Keith Cowing
Status Report
astro-ph.EP
January 20, 2023
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Biosignature Line Ratios Of [P II] In Exoplanetary And Nebular Environments
Energy diagram of P ii showing the fine structure levels in the ground configuration 3s 23p 2 , and a few transitions in the JWST wavelength range. — astro-ph.EP

Being the backbone element of DNA, phosphorus is a key component in the search for life in the Universe.

Being the backbone element of DNA, phosphorus is a key component in the search for life in the Universe. To aid in its detection, we present line emissivity ratios for the five lowest-lying forbidden [P~II] transitions, namely those among the levels 3s23p2(3P0,3P1,3P2,1D2,1S0).

The wavelengths range between 0.44-70 \mum, and several lie within the spectroscopic domain observable with the James Webb Space Telescope (JWST). These line ratios have been calculated using a new collisional-radiative-recombination (CRR) model combining calculated collision strengths and level-specific recombination rate coefficients; with both datasets computed using the accurate Breit-Pauli R-Matrix method.

The CRR model includes a new scheme for \eion recombination to emission line formation. We compare its effect to models incorporating only electron impact excitation and spontaneous radiative decay. We find that electron-ion recombination has a significant impact on all line ratios, and represents a major improvement in physical accuracy of emission line models.

Kevin Hoy, Sultana N. Nahar, Anil K. Pradhan

Comments: 5 pages, 4 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2301.07736 [astro-ph.EP] (or arXiv:2301.07736v1 [astro-ph.EP] for this version)
Submission history
From: Anil K. Pradhan
[v1] Wed, 18 Jan 2023 19:01:25 UTC (484 KB)
https://arxiv.org/abs/2301.07736
Astrobiology, Astrochemistry

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