123-321 Models of Classical Novae

Abstract

High-resolution spectroscopy has revealed large concentrations of CNO and sometimes other intermediate-mass elements in the shells ejected during nova outbursts, suggesting that the solar composition material transferred from the secondary mixes with the outermost layers of the underlying white dwarf during the thermonuclear runaway. Multidimensional simulations have shown that Kelvin-Helmholtz instabilities provide self-enrichment of the accreted envelope with material from the outermost layers of the white dwarf, at levels that agree with observations. However, the Eulerian and time-explicit nature of most multidimensional codes used to date and the overwhelming computational load have limited their applicability, and no multidimensional simulation has been conducted for a full nova cycle. This paper explores a new methodology that combines 1-D and 3-D simulations. The early stages of the explosion (i.e., mass-accretion and initiation of the runaway) have been computed with the 1-D hydrodynamic code SHIVA. When convection extends throughout the entire envelope, the structures for each model were mapped into 3-D Cartesian grids and were subsequently followed with the multidimensional code FLASH. Two key physical quantities were extracted from the 3-D simulations and subsequently implemented into SHIVA, which was used to complete the simulation through the late expansion and ejection stages: the time-dependent amount of mass dredged-up from the outer white dwarf layers, and the time-dependent convective velocity profile throughout the envelope. More massive envelopes than those reported from previous models with pre-enrichment have been found. This results in more violent outbursts, characterized by higher peak temperatures and greater ejected masses, with metallicity enhancements in agreement with observations.

8 pages, accepted for publication in Astronomy & Astrophysics

References in corpus (1)

• On mixing at the core-envelope interface during classical nova outbursts

Cited by in corpus (13)

• The evolution of CNO elements in galaxies
• Localised thermonuclear bursts from accreting magnetic white dwarfs
• Study of 2021 outburst of the recurrent nova RS Ophiuchi: Photoionization and morpho-kinematic modelling
• Physics of nova outbursts: A theoretical model of classical nova outbursts with self-consistent wind mass loss
• Detection of ${}^7$Be II in the Classical Nova V5669 Sgr (Nova Sagittarii 2015 No.3)
• In-depth Analysis of Evolving Binary Systems that Produce Nova Eruptions
• Detection of ${}^7$Be II in the Small Magellanic Cloud
• Novae: An Important Source of Lithium in the Galaxy
• The Peculiar Bursting Nature of CP Pup
• Thermonuclear reaction rate of ${}^{29}$Si(p,$\gamma$)${}^{30}$P
• Hydrogen burning of ${}^{29}$Si and its impact on presolar stardust grains from classical novae
• Triggering micronovae through magnetically confined accretion flows in accreting white dwarfs
• Viability of novae as sources of Galactic lithium