http://arxiv.org/abs/1402.6672
We perform population synthesis simulations for Population III~(Pop III) coalescing binary neutron stars~(NS-NSs), neutron star – black hole binaries~(NS-BHs), and binary black holes~(BH-BHs) which merge within the age of the universe. We upgrade the open numerical code (Hurley et al. 2002) for Population I~(Pop I) stars to Pop III stars. We found that the typical mass of Pop III BH-BHs is $\sim 30\ \rm{M}_{\odot}$ so that the inspiral chirp signal of gravitational waves can be detected up to z=0.28 by KAGRA, Adv. LIGO, Adv. Virgo and GEO network. Our new simulations suggest that the detection rate of the coalescing Pop III BH-BHs is $140~(68) \cdot ({\rm SFR}_{\rm p}/10^{-2.5}~\rm{M}_{\odot}~{\rm yr}^{-1}~{\rm Mpc}^{-3}) \cdot {\rm Err}_{\rm sys}~{\rm events}~{\rm yr}^{-1}$ for the flat (Salpeter) initial mass function~(IMF), respectively, where $\rm SFR_p$ and $\rm Err_{sys}$ are the peak value of the Pop III star formation rate and the possible systematic errors due to the assumptions in Pop III population synthesis, respectively. For Einstein Telescope, the detection rate is $\sim$ 80 times more and the detection range is up to $z\sim 3$. From the observation of the chirp signal of the coalescing Pop III BH-BHs, we can determine both the mass and the redshift of the binary for the cosmological parameters determined by Planck satellite. Our simulations suggest that the cumulative redshift distribution of the coalescing Pop III BH-BHs depends almost only on the cosmological parameters. We might be able to confirm the existence of PopIII massive stars of mass $\sim 30~\rm{M}_{\odot}$ by the detections of gravitational waves if the merger rate of the Pop III massive BH-BHs dominates that of Pop I BH-BHs.
T. Kinugawa, K. Inayoshi, K. Hotokezaka, et. al.
Thu, 27 Feb 14
57/59
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