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Polarized Gravitational Waves from Gamma-Ray Bursts. Shiho Kobayashi (Penn State) Peter Meszaros (Penn State). ApJ 585(2003)L89. GRB Engine: Rotating BH+massive AD. Compact Stellar Mergers. Fast-Rotating Massive Stellar Collapses. Compact Stellar Mergers Strong GW Sources
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Polarized Gravitational Wavesfrom Gamma-Ray Bursts Shiho Kobayashi (Penn State) Peter Meszaros (Penn State) ApJ 585(2003)L89
GRB Engine: Rotating BH+massive AD Compact Stellar Mergers Fast-Rotating Massive Stellar Collapses
Compact Stellar Mergers Strong GW Sources Inspiral, Merging and Ring-down Phases Fast-Rotating Massive Stellar Collapses Possibly Strong GW Sources Bar and Fragmentation Instabilities
(1) GRB progenitors are stronger GW sources than the average nonbursting mergers or collapsars (2) GRB luminosity and GW polarization GRB Jet Linear Polarization Degree Recent GRB observations GRB luminosity is determined by the jet opening angle or the viewing angle
Polarization Measurement (1) two interferometers (rotated by ) (2) optimal case: wave forms are known (3) For simplicity, GW source is in the direction of z-axis. (GRB, afterglow: sky position) output Interferometer 1 Liner Polarization Degree Interferometer 2 are NOT observable, so that 1% polarization :
Interferometer identical to LIGO ( rotated by ) If some fraction of GRB progenitors are DNSs... Viewing angle : larger by a factor In an optimal case , we can determine 1% polarization degree up 7 Mpc. 1000 GRBs/year/(3000Mpc) the closest event in a year d=30Mpc sky position random: correction measure 1% Polarization in a timescale of 1yr: 3
Summary Correlation among Luminosity of GRB, the amplitude as well as the polarization of GW is expected. Brigher GRB: stronger circular polarized GW LIGO-like interferometer Optimal case: 1% polarization in GW from DNS at 7Mpc To detect 1% polarization in yr timescale