NORMAL TYPE Ia SUPERNOVAE FROM VIOLENT MERGERS OF WHITE DWARF BINARIES

Journal Article · Thu Mar 15 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/747/1/L10· OSTI ID:22048011

Pakmor, R ^[1]; Kromer, M; Taubenberger, S; Hillebrandt, W ^[2]; Sim, S A ^[3]; Roepke, F K ^[4]

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1. Heidelberger Institut fuer Theoretische Studien, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg (Germany)
2. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)
3. Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia)
4. Institut Fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg, Emil-Fischer-Str. 31, 97074 Wuerzburg (Germany)

One of the most important questions regarding the progenitor systems of Type Ia supernovae (SNe Ia) is whether mergers of two white dwarfs can lead to explosions that reproduce observations of normal events. Here we present a fully three-dimensional simulation of a violent merger of two carbon-oxygen white dwarfs with masses of 0.9 M{sub Sun} and 1.1 M{sub Sun} combining very high resolution and exact initial conditions. A well-tested combination of codes is used to study the system. We start with the dynamical inspiral phase and follow the subsequent thermonuclear explosion under the plausible assumption that a detonation forms in the process of merging. We then perform detailed nucleosynthesis calculations and radiative transfer simulations to predict synthetic observables from the homologously expanding supernova ejecta. We find that synthetic color light curves of our merger, which produces about 0.62 M{sub Sun} of {sup 56}Ni, show good agreement with those observed for normal SNe Ia in all wave bands from U to K. Line velocities in synthetic spectra around maximum light also agree well with observations. We conclude that violent mergers of massive white dwarfs can closely resemble normal SNe Ia. Therefore, depending on the number of such massive systems available these mergers may contribute at least a small fraction to the observed population of normal SNe Ia.

• OSTI ID: 22048011
• Journal Information: Astrophysical Journal Letters, Vol. 747, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
CARBON
COLOR
COMPUTER CODES
COMPUTERIZED SIMULATION
HYDRODYNAMICS
MASS
NICKEL 56
NUCLEOSYNTHESIS
OXYGEN
RADIANT HEAT TRANSFER
RESOLUTION
SUPERNOVAE
THERMONUCLEAR EXPLOSIONS
THREE-DIMENSIONAL CALCULATIONS
VISIBLE RADIATION
WHITE DWARF STARS