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A burst from a thermonuclear runaway on an ONeMg white dwarfStudies which examine the consequences of accretion, at rates of 10(exp -9) solar mass/yr and 10(exp -10) solar mass/yr, onto an ONeMg white dwarf with a mass of 1.35 solar masses are performed. In these studies, a Lagrangian, hydrodynamic, one-dimensional computer code was used. The code now includes a network with 89 nuclei up to Ca-40, elemental diffusion, new opacities, and new equation of state. The initial abundance distribution corresponded to a mixture that was enriched to either 25, 50, or 75 percent in products of carbon burning. The remaining material in each case is assumed to have a solar composition. The evolution of the thermonuclear runaway in the 1.35 solar mass white dwarf, with M = 10(exp -9) solar mass, produced peak temperatures in the shell source exceeding 300 million degrees. The sequence produced significant amounts of Na-22 from proton captures onto Ne-20 and significant amounts of Al-26 from proton captures on Mg-24. This sequence ejected 5.2 x 10(exp -6) solar mass moving with speeds from approximately 100 km/s to 2300 km/s. When the mass accretion rate was decreased to 10(exp -10) solar mass, the resulting thermonuclear runaway produced a shock that moved through the outer envelope of the white dwarf and raised the surface luminosity to L greater than 10(exp 7) solar luminosity and the effective temperature to values exceeding 10(exp 7) K. The interaction of the material expanding from off of the white dwarf with the accretion disk should produce a burst of gamma-rays.
Document ID
19920012682
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Starrfield, S. (Los Alamos National Lab. NM., United States)
Politano, M. (Arizona State Univ. Tempe., United States)
Truran, J. W. (Chicago Univ. IL., United States)
Sparks, W. M. (Los Alamos National Lab. NM., United States)
Date Acquired
September 6, 2013
Publication Date
February 1, 1992
Publication Information
Publication: NASA. Goddard Space Flight Center, The Compton Observatory Science Workshop
Subject Category
Space Radiation
Accession Number
92N21925
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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