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Gravitational Radiation from Magnetorotational Supernovae. Avetis Abel Sadoyan (YSU), Sergey Moiseenko( IKI- Space Research Institute, Moscow)
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ΕΛΕΓΕ ΔΕ ΚΑΙ ΔΩΡΙΣΤΙ ΦΩΝΗ ΣΥΡΑΚΟΥΣΙΑ, “ΠΑ ΒΩ ΚΑΙ ΧΑΡΙΣΤΙΩΝΙ ΤΑΝ ΓΑΝ ΚΙΝΗΣΩ ΠΑΣΑΝ.” “Give me a place to stand and with a lever I will move the whole world.” Give me oscillation frequencies and Quadrupole moments of the configuration and I will describe the Gravitational Radiation Source
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Zeldovich approach Self-Similar Oscillations: §Coordinates changes: § is amplitude of oscillation, is frequency. §We speculate that oscillations are smooth- the system returns in initial stage §To estimate the upper limits of GW radiation of a source, its enough to calculate the radiation during self similar oscillations.
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Quadrupole Moments Quadruple Moments are taking an “esthetically nice” time dependent form that simplifies equations
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Power of Gravitational Radiation §Gravitation radiation intensity is equal to : § Using the eq. for Quadruple moment one can easily obtain
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Calculation of GW amplitudes
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GW Amplitudes and SS Oscillation Amplitudes are:
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How does the method works for White Dwarfs?
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9 White Dwarf Properties and Resonant Frequencies c (g/cm 3 ) M 0 (M ) M (M ) Ω max Q 0 max (10 48 g cm 2 ) N (57) 1.76 10 6 0.4980.5720.19620.480.49970.757 1.54 10 7 0.8670.9760.47614.270.83980.766 1.28 10 8 1.1451.2541.0634.7661.06951.399 7.036 10 8 1.2451.342.0421.5541.13402.001 2.09 10 9 1.2571.3393.1050.6731.12611.299
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May 30, 2006Gravitational Wave Advanced Detectors Workshop 10 GW Amplitudes from WDs rotating with Keplerian angular velocities
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Lets turn now to Magnetorotational Supernova
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What is Magnetorotational supernova? “…Mechanism that involves the transfer of angular momentum of newly born and rapidly rotating Neutron star to the envelope, where centrifugal force is nearly equal to the gravitational force. An explosion with a generated shockwave will take place, when centrifugal force inside the envelope exceed the gravitational force. Angular momentum will be transferred efficiently ONLY if sufficiently strong Magnetic field, H~3 10 ^ 9 Gauss is present. Bisnovatyi-Kogan Astronomicheski Zhurnal, Vol 47,No.4, pp.813-816 July- August, (1970) (original article was submitted: September 3, 1969) LeBlanck&Wilson (1970) )(original article was submitted: September 25, 1969) Small initial magnetic field -is the main difficulty for the numerical simulations.
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Numerical simulations Lagrangian, implicit, triangular grid with rezoning, completely conservative
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Initial state, spherically symmetrical stationary state, initial angular velocity 2.519 (1/sec) Initial temperature distribution
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Maximal compression state Max. density = 2.5·10 14 g/cm 3
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Neutron star formation in the center and formation of the shock wave «0.01»~10km
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Mixing
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Temperature and velocity field Angular velocity.Specific angular momentum
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Frequencies for self-similar oscillations of the configuration
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Whats happening with the system?
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Quadrupole moments of the configuration
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§We can distinguish two time periods of GW Radiation: accretion Driven and magnetorotation
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Amplitudes of GW Radiation
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Conclusions §Magnetoratating Supernova are Extensively strong sourced of GW Radiation with amplitudes around 10^-19, in LIGO frequency band
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