Talk abstract details

Detections of gravitational waves (GWs) from nearby core-collapse supernovae are now becoming reality. Since GWs (plus neutrinos) can be the only window that enables us to see directly the innermost part of evolved massive stars, their information is expected to give us clues to the long veiled problems, such as the angular momentum distributions, properties of nuclear equations of state, and ultimately the explosion mechanisms.

So far we have done a series of (magneto)hydrodynamic simulations of gravitational core-collapse of massive stars not only for the understanding of the formation mechanism of compact objects such as neutron/quark stars (Yasutake, Kotake, Hashimoto, Yamada, PRD in press), and black holes, but also for studying the properties of waveforms of GWs (see for a review Kotake et al. Rep. Prog. Phys, 69, 971, (2006)). In this contribution, we first review such studies about GWs.

In addition to the GWs emitted at core-bounce, recent attentions have been paid to the GWs generated from the anisotropic neutrino radiation generated more later phase after core-bounce. Such gravitational waves have the so-called memory effects and their waveforms are completely different from the bounce signals. To study this, we performed long-term simulations of supernova cores long after core-bounce and found that such GWs (typical frequencies of 100 Hz) can be within the detection limits of the next-generation GW detector such as the advanced LIGO and LCGT (Kotake et al. ApJ in press) for a galactic supernova. Moreover, we recently estimated the contributions of the neutrino-originated GWs from the Pop III stars (Suwa, Takiwaki, Kotake, Sato, PASJ in press) as a cosmological gravitational wave background (GWBG) and found that they could be an obstacle for the detection of GWBG generated at the inflationary epoch (to be submitted to ApJL). We would like to present these results in this contribution.