Photoionization modeling of the dusty nova V1280 Scorpii

TL;DR

This study models the physical and chemical evolution of the dusty nova V1280 Scorpii using photoionization simulations to understand changes before and after dust formation, revealing high densities, dust composition, and elemental abundances.

Contribution

It provides the first detailed photoionization model of V1280 Sco that captures the physical conditions and dust properties during different phases of the nova.

Findings

Central source temperature and luminosity increase post-dust formation.

High ejecta densities are necessary for spectral modeling.

Presence of mixed dust grains and high elemental abundances in ejecta.

Abstract

We perform photoionization modeling of the dusty nova V1280 Scorpii (V1280 Sco) with an aim to study the changes in the physical and chemical parameters. We model pre and post dust phase, optical and near-Infrared (NIR), spectra using the photoionization code \textsc{cloudy}, v.17.02, considering a two-component (low density and high density region) model. From the best-fit model, we find that the temperature and luminosity of the central ionizing source in the pre-dust phase are in the range 1.32 - 1.50 $\times 10^4$ K and 2.95 - 3.16 $\times 10^{36}$ ergs$^{-1}$, respectively, which increase to 1.58 - 1.62 $\times 10^4$ K and 3.23 - 3.31 $\times 10^{36}$ ergs$^{-1}$, respectively, in the post-dust phase. It is found that a very high hydrogen density ($\sim 10^{13} - 10^{14}$ cm$^{-3}$) is required for the generation of spectra properly. Dust condensation conditions are achieved at high ejecta density ($\sim 3.16 \times 10^{8}$cm$^{-3}$) and low temperature ($\sim$2000 K) in the outer region of the ejecta. It is found that a mixture of small (0.005 - 0.25$\mu$m) amorphous carbon dust grains and large (0.03 - 3.0$\mu$m) astrophysical silicate dust grains iis present n the ejecta in the post-dust phase. Our model yields very high elemental abundance values as C/H = 13.5 - 20, N/H = 250, O/H = 27 - 35, by number, relative to solar in the ejecta, during the pre-dust phase, which decrease in the post-dust phase.