The panchromatic spectroscopic evolution of the classical CO nova V339 Del (Nova Del 2013) until X-ray turnoff

TL;DR

This study provides a comprehensive spectroscopic analysis of the classical nova V339 Del, covering early outburst to X-ray turnoff, using multi-wavelength data to understand ejecta properties and evolution.

Contribution

First detailed multi-wavelength spectroscopic dataset of V339 Del covering early to X-ray phases, with modeling of ejecta structure and properties.

Findings

Ejecta electron densities and temperatures constrained.

Ejecta structure and mass derived from line profile modeling.

Spectroscopic evolution documented from outburst to X-ray phase.

Abstract

Classical novae are the product of thermonuclear runaway-initiated explosions occurring on accreting white dwarfs. V339 Del (Nova Delphinus 2013) was one of the brightest classical novae of the last hundred years. Spectroscopy and photometry are available from $\gamma$-rays through infrared at stages that have frequently not been well observed. The complete data set is intended to provide a benchmark for comparison with modeling and for understanding more sparsely monitored historical classical and recurrent novae. This paper is the first in the series of reports on the development of the nova. We report here on the early stages of the outburst, through the X-ray active stage. A time sequence of optical, flux calibrated high resolution spectra was obtained with the Nordic Optical Telescope (NOT) using FIES simultaneously, or contemporaneously, with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope during the early stages of the outburst. These were supplemented with MERCATOR/HERMES optical spectra. High resolution IUE ultraviolet spectra of OS And 1986, taken during the Fe curtain phase, served as a template for the distance determination. We used standard plasma diagnostics (e.g., [O III] and [N II] line ratios, and the H$\beta$ line flux) to constrain electron densities and temperatures of the ejecta. Using Monte Carlo modeling of the ejecta, we derived the structure, filling factor, and mass from comparisons of the optical and ultraviolet line profiles.