Gravitational Radiation from Collapsing Magnetized Dust. II -- Polar Parity Perturbation --

With the gauge-invariant perturbation theory, we study the effects of the stellar magnetic fields on the polar gravitational waves emitted during the homogeneous dust collapse. We found that the emitted energy in gravitational waves depends strongly not only on the initial stellar radius but also on the rasio between the poloidal and toroidal magnetic components. The polar gravitational wave output of such a collapse can be easily up to a few order of magnitude larger than what we get from the nonmagnetized collapse. The changes due to the existence of magnetic field could be helpful to extract some information of inner magnetic profiles of progenitor from the detection of the gravitational waves radiated during the black hole formation, which results from the stellar collapse.