A MODEL FOR GRAVITATIONAL WAVE EMISSION FROM NEUTRINO-DRIVEN CORE-COLLAPSE SUPERNOVAE

Journal Article · Sun Dec 20 00:00:00 EST 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/707/2/1173· OSTI ID:21392586

Murphy, Jeremiah W ^[1]; Ott, Christian D ^[2]; Burrows, Adam ^[3]

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1. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States)
2. Theoretical Astrophysics, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125 (United States)
3. Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States)

Using a suite of progenitor models, neutrino luminosities, and two-dimensional simulations, we investigate the matter gravitational wave (GW) emission from postbounce phases of neutrino-driven core-collapse supernovae. These phases include prompt and steady-state convection, the standing accretion shock instability (SASI), and asymmetric explosions. For the stages before explosion, we propose a model for the source of GW emission. Downdrafts of the postshock-convection/SASI region strike the protoneutron star 'surface' with large speeds and are decelerated by buoyancy forces. We find that the GW amplitude is set by the magnitude of deceleration and, by extension, the downdraft's speed and the vigor of postshock-convective/SASI motions. However, the characteristic frequencies, which evolve from approx100 Hz after bounce to approx300-400 Hz, are practically independent of these speeds (and turnover timescales). Instead, they are set by the deceleration timescale, which is in turn set by the buoyancy frequency at the lower boundary of postshock convection. Consequently, the characteristic GW frequencies are dependent upon a combination of core structure attributes, specifically the dense-matter equation of state (EOS) and details that determine the gradients at the boundary, including the accretion-rate history, the EOS at subnuclear densities, and neutrino transport. During explosion, the high frequency signal wanes and is replaced by a strong low frequency, approx10s of Hz, signal that reveals the general morphology of the explosion (i.e., prolate, oblate, or spherical). However, current and near-future GW detectors are sensitive to GW power at frequencies approx>50 Hz. Therefore, the signature of explosion will be the abrupt reduction of detectable GW emission.

• OSTI ID: 21392586
• Journal Information: Astrophysical Journal, Vol. 707, Issue 2; Other Information: DOI: 10.1088/0004-637X/707/2/1173; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCELERATION
AMPLITUDES
ASYMMETRY
CONVECTION
COSMIC NEUTRINOS
EMISSION
EQUATIONS OF STATE
EXPLOSIONS
GRAVITATIONAL WAVES
HYDRODYNAMICS
LUMINOSITY
MATTER
MORPHOLOGY
SHOCK WAVES
SIGNALS
SIMULATION
STEADY-STATE CONDITIONS
SUPERNOVAE
TURBULENCE
TWO-DIMENSIONAL CALCULATIONS
BINARY STARS
COSMIC RADIATION
ELEMENTARY PARTICLES
ENERGY TRANSFER
EQUATIONS
ERUPTIVE VARIABLE STARS
FERMIONS
FLUID MECHANICS
HEAT TRANSFER
IONIZING RADIATIONS
LEPTONS
MASS TRANSFER
MASSLESS PARTICLES
MECHANICS
NEUTRINOS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
STARS
VARIABLE STARS