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Title: Oblique shock breakout in supernovae and gamma-ray bursts. I. Dynamics and observational implications

In a non-spherical stellar explosion, non-radial motions become important near the stellar surface. For realistic deviations from spherical symmetry, non-radial flow dramatically alters the dynamics and emission of shock emergence on a significant fraction of the surface. The breakout flash is stifled, ejecta speeds are limited, and matter is cast sideways. Non-radial ejection allows for collisions outside the star, which may engender a new type of transient. Strongly oblique breakouts are most easily produced in compact stellar progenitors, such as white dwarfs and stripped-envelope core-collapse supernovae. We study the shock structure and post-shock acceleration using conservation laws, a similarity analysis, and an approximate theory for oblique shocks. The shock is likely to extend vertically from the stellar surface, then kink before joining a deep asymptotic solution. Outflow from the region crossed by an oblique shock is probably unsteady and may affect the surface ahead of the main shock. We comment on the implications for several notable explosions in which the non-spherical dynamics described in this paper are likely to play an important role. We also briefly consider relativistic and superluminal pattern speeds.
Authors:
;  [1] ;  [2]
  1. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George St., Toronto, ON M5S 3H4 (Canada)
  2. Monash Centre for Astrophysics, Monash University, Clayton, VIC 3800 (Australia)
Publication Date:
OSTI Identifier:
22348530
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 779; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; APPROXIMATIONS; ASYMPTOTIC SOLUTIONS; COMPACTS; COSMIC GAMMA BURSTS; EMISSION; EXPLOSIONS; HYDRODYNAMICS; RELATIVISTIC RANGE; SHOCK WAVES; SPHERICAL CONFIGURATION; SUPERNOVAE; SURFACES; SYMMETRY; TRANSIENTS; WHITE DWARF STARS; X RADIATION