Photoionization modeling of the dusty nova V1280 Scorpii

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 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 is in the range 1.32 -1.50 ×10 4 K and 2.95 -3.16 ×10 36 ergs −1 , respectively, which increase to 1.58 -1.62 ×10 4 K and 3.23 -3.31 ×10 36 ergs −1 , respectively, in the post-dust phase. It is found that a very high hydrogen density (∼ 10 13 − 10 14 cm −3 ) is required for the generation of spectra properly. Dust condensation conditions are achieved at high ejecta density (∼ 3.16 × 10 8 cm −3 ) and low temperature (∼2000 K) in the outer region of the ejecta. It is found that a mixture of small (0.005 -0.25µm) amorphous carbon dust grains and large (0.03 -3.0µm) astrophysical silicate dust grains iis present n the ejecta in the post-dust phase. Our model yields a 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.