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The Nova Project

A collaboration between JINA, TRIUMF, UVic (Lead scientist: Pavel Denisenkov , UVic ). The Nova Project. Project update February 2012. The Nova modeling framework

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The Nova Project

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  1. A collaboration between JINA, TRIUMF, UVic (Lead scientist: PavelDenisenkov, UVic) The Nova Project Project update February 2012. The Nova modeling framework Over the first year of operation we have built The Nova Framework for simulations of the evolution and nucleosynthesis of nova. It combines the stellar evolution code MESA (http://mesa.sourceforge.net), the post-processing nucleosynthesis code suite NuGrid (http://www.astro.keele.ac.uk/nugrid) including associated visualization tools, and user-friendly shell scripts. Detailed instructions on its installation and operation, as well as demo movies are available at http://astro.triumf.ca/nova-framework. The Nova Framework has been used as a research tool to investigate the evolution and mixing in CO-WD nova for a wide range of parameters. The results have been written up (a paper is ready for submission to ApJ). A demo installation of The Nova Framework is currently installed on a dedicated TRIUMF server. Multi-cycle evolution of 1.2MsunCO nova models. Tc=3 (red,green) and 1.5 * 107K (blue), accreted material solar comp (red,blue) and 30% CO WD comp. admixture (green).

  2. The Nova Project • Main results • 22 multi-cycle nova evolution sequences with CO WD cores computed • Establishing and documenting trends in nova properties as a function of CO WD masses, central temperatures, and accretion rates and accretion material (solar and CO pre-enriched). • Extensive verification with previous results, e.g. from Glasner & Truran, show good agreement between modeling approaches. • Models with convective boundary mixing at the bottom of the H-flash convection zone has been shown to lead to metal enrichment of the envelope (ZCO=0.29) and nova explosion strength that compare well with observations. • New mechanism for nova for slow accretion on very cold CO: incomplete pp-chain reactions deposit 3He at the bottom of the accreted envelope, ignites and triggers convection at T=40 MK. Formation of 3He at the bottom of accretion layer, ignition and formation of convection zone that will dredge-up CO material and trigger the main TNR. • Next steps • ONeMg Nova models. • Comprehensive nucleosynthesis computations and rate-sensitivity evaluations for both CO- and ONeMg nova models. • Investigation of hydrodynamic porperties of • Convection properties • Ejection and reverse common envelope

  3. Nova Framework verification The Nova Project Comparison of envelope abundances in a CO nova with boundary mixing (top: Barcelona group; bottom: Nova Project) Comparison of luminosities and temperatures for similar nova flashes from Nova Project (top) and and Ami Glasner (bottom). MESA nova simulation post-processed NuGrid codes involving complete network.

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