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Title: ZERO IMPACT PARAMETER WHITE DWARF COLLISIONS IN FLASH

Abstract

We systematically explore zero impact parameter collisions of white dwarfs (WDs) with the Eulerian adaptive grid code FLASH for 0.64 + 0.64 M {sub Sun} and 0.81 + 0.81 M {sub Sun} mass pairings. Our models span a range of effective linear spatial resolutions from 5.2 Multiplication-Sign 10{sup 7} to 1.2 Multiplication-Sign 10{sup 7} cm. However, even the highest resolution models do not quite achieve strict numerical convergence, due to the challenge of properly resolving small-scale burning and energy transport. The lack of strict numerical convergence from these idealized configurations suggests that quantitative predictions of the ejected elemental abundances that are generated by binary WD collision and merger simulations should be viewed with caution. Nevertheless, the convergence trends do allow some patterns to be discerned. We find that the 0.64 + 0.64 M {sub Sun} head-on collision model produces 0.32 M {sub Sun} of {sup 56}Ni and 0.38 M {sub Sun} of {sup 28}Si, while the 0.81 + 0.81 M {sub Sun} head-on collision model produces 0.39 M {sub Sun} of {sup 56}Ni and 0.55 M {sub Sun} of {sup 28}Si at the highest spatial resolutions. Both mass pairings produce {approx}0.2 M {sub Sun} of unburned {sup 12}C+{sup 16}O. Wemore » also find the 0.64 + 0.64 M {sub Sun} head-on collision begins carbon burning in the central region of the stalled shock between the two WDs, while the more energetic 0.81 + 0.81 M {sub Sun} head-on collision raises the initial post-shock temperature enough to burn the entire stalled shock region to nuclear statistical equilibrium.« less

Authors:
; ;  [1]
  1. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)
Publication Date:
OSTI Identifier:
22086482
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 759; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; CARBON 12; CARBON BURNING; COLLISIONS; COMPUTERIZED SIMULATION; ELEMENT ABUNDANCE; F CODES; IMPACT PARAMETER; NICKEL 56; OXYGEN 16; SILICON 28; SPATIAL RESOLUTION; SUPERNOVAE; WHITE DWARF STARS

Citation Formats

Hawley, W. P., Athanassiadou, T., and Timmes, F. X., E-mail: Wendy.Hawley@asu.edu. ZERO IMPACT PARAMETER WHITE DWARF COLLISIONS IN FLASH. United States: N. p., 2012. Web. doi:10.1088/0004-637X/759/1/39.
Hawley, W. P., Athanassiadou, T., & Timmes, F. X., E-mail: Wendy.Hawley@asu.edu. ZERO IMPACT PARAMETER WHITE DWARF COLLISIONS IN FLASH. United States. doi:10.1088/0004-637X/759/1/39.
Hawley, W. P., Athanassiadou, T., and Timmes, F. X., E-mail: Wendy.Hawley@asu.edu. Thu . "ZERO IMPACT PARAMETER WHITE DWARF COLLISIONS IN FLASH". United States. doi:10.1088/0004-637X/759/1/39.
@article{osti_22086482,
title = {ZERO IMPACT PARAMETER WHITE DWARF COLLISIONS IN FLASH},
author = {Hawley, W. P. and Athanassiadou, T. and Timmes, F. X., E-mail: Wendy.Hawley@asu.edu},
abstractNote = {We systematically explore zero impact parameter collisions of white dwarfs (WDs) with the Eulerian adaptive grid code FLASH for 0.64 + 0.64 M {sub Sun} and 0.81 + 0.81 M {sub Sun} mass pairings. Our models span a range of effective linear spatial resolutions from 5.2 Multiplication-Sign 10{sup 7} to 1.2 Multiplication-Sign 10{sup 7} cm. However, even the highest resolution models do not quite achieve strict numerical convergence, due to the challenge of properly resolving small-scale burning and energy transport. The lack of strict numerical convergence from these idealized configurations suggests that quantitative predictions of the ejected elemental abundances that are generated by binary WD collision and merger simulations should be viewed with caution. Nevertheless, the convergence trends do allow some patterns to be discerned. We find that the 0.64 + 0.64 M {sub Sun} head-on collision model produces 0.32 M {sub Sun} of {sup 56}Ni and 0.38 M {sub Sun} of {sup 28}Si, while the 0.81 + 0.81 M {sub Sun} head-on collision model produces 0.39 M {sub Sun} of {sup 56}Ni and 0.55 M {sub Sun} of {sup 28}Si at the highest spatial resolutions. Both mass pairings produce {approx}0.2 M {sub Sun} of unburned {sup 12}C+{sup 16}O. We also find the 0.64 + 0.64 M {sub Sun} head-on collision begins carbon burning in the central region of the stalled shock between the two WDs, while the more energetic 0.81 + 0.81 M {sub Sun} head-on collision raises the initial post-shock temperature enough to burn the entire stalled shock region to nuclear statistical equilibrium.},
doi = {10.1088/0004-637X/759/1/39},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}